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Description
420 Mystery BoxWhile Supplies Last. Only 50 Available! 420 Mystery Boxes contain grinders & accessories valued at more than $140 MSRP. The size and color of the grinders is the mystery you will uncover on arrival! We guarantee two different colors and sizes. Each Mystery Box Contains 1 x 4 Piece Grinder + Upgrade Kit 1 x 2 Piece Grinder + Bumper Rings Sticker Pack Cash in on huge savings and secure yourself the perfect grinder setup. Most grinders won't last you a
While Supplies Last. Only 50 Available!
420 Mystery Boxes contain grinders & accessories valued at more than $140 MSRP. The size and color of the grinders is the mystery you will uncover on arrival! We guarantee two different colors and sizes.
Each Mystery Box Contains
- 1 x 4 Piece Grinder + Upgrade Kit
- 1 x 2 Piece Grinder + Bumper Rings
- Sticker Pack
Cash in on huge savings and secure yourself the perfect grinder setup.
Most grinders won't last you a whole year, while a Phoenician will last you a LIFETIME.
Proudly backed by a Limited Lifetime Warranty.
Final Sale
No Additional Discounts
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.2 ★★★★★
Based on 1851 reviews
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Product Reviews
★★★★★ 5
Very good product at a fair price
Model: SLH20025
Very good sound deadener and heat shield, it is a bit sticky to work with, but easy to shape and cut
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Reviewed in the United States on April 19, 2026
★★★★★ 5
I wish I had Siless 20 years ago!!!
Model: SLH20025, Model: SLH20025
I have installed all kinds of insulation in vehicles over many years. I only needed to purchase 2 boxes to complete the entire interior siding of my 2025 chevy express, what a great value! I wanted to insulate my locksmith van for sound and heat. The sound reduction virtually eliminated the road noise. These panels also look amazing. It got up to 110F in the sun with the doors closed. After adding Siless insulation the temperature maxed out at 97F. That is a massive difference. Plus, I didn't even finish with the roof before testing. Siless Hybrid 3in1 was extremely easy to cut and adhere onto metal panels. I'm impressed with the quality of the individual panels and the adhesive is not toxic smelling compared to some others. My favorite thing about these panels is you can actually take them off and readjust them before they finally stick and they do not leave any black residue behind when you pull them up to adjust them. All I needed was a heat gun, knife and a roller to complete this job. The size of each panel is perfect, you can handle them with ease. I probably won't need your product again for a while, but when I do I will definitely be back.
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Reviewed in the United States on September 21, 2025
★★★★★ 5
Works well and is easy to install.
Model: SLH20025, Model: SLH20025
I was sound and heat insulating a generator bay in my class A RV so I did three tests before and during material application: I did a sound level test to see how effective the material was for my application, a "stickiness" test, and a flammability test. This was indoors on a dry 78°F day. From beginning to end, the entire process, including testing, took 5 hours to install 25 sqft or material in a very complex area. One hour for cleaning, 3 hours for installation, and 1 hour for test setup and testing.
Using a sound meter, I took before and after readings and determined that I reduced the sound level by 2.2 db (40% energy decrease) with a noticeable decrease in sound and frequency. The generator bay is located under the master bedroom in the aft portion of the coach. The sound went from a rattling, vibrating generator noise to a more tolerable low level rumble.
The material was easy to apply. I did some testing prior to application and determined that surface preparation is key. I cleaned my painted metal surface and then degreased with acetone and the material stuck well. Be careful and purposeful when you apply the material because once it was stuck to the metal, it was quite difficult to remove or reposition.
Since it was going to be installed into a gasoline powered generator bay located under our sleeping quarters, I did some flame testing to determine the level of risk. Although not highly flammable after installation, my testing revealed that the PE used will catch on fire under certain circumstances. In order to reduce the risk, I used aluminized duct tape to ensure that all the edges were sealed and the PE was not exposed to direct flame in the event of a fire. I also decided to install an automatic fire extinguisher as an added precaution. In all fairness there should be one installed in the generator bay anyway.
All in all, I am very satisfied with the product and the results. I have recommended this product to my other RV owner friends.
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Reviewed in the United States on April 13, 2025
★★★★★ 5
Great product. Best value i could find
Model: SLH20025
I'm using talk to text, so forgive any grammatical and spelling errors.
I ordered this product after doing a bit of research on sound dampening materials. I had been doing car stereo for quite some time since my teens. Itook a break for 20 years or so. I'm now 40 and back in the day there was dynamat. And that was about it. as irecently bought a new 2017 F350 crew cab. I wanted to put in a new stereo system and being that it was my dream truck. I was going to put in my dream stereo. But before I could do that, I needed to start with the sound deadening. I looked into today's leading product and found a company called resonx. Had taken their place as king of the hill in sound deadly. I researched their products and found the materials they were built from and Silas was the closest match at the best price I used Silas Max. First, then Silas 3 and 1 hybrid over that on all exterior panels. Then, on the interior panels. I used the 3 and 1 hybrid . on the floor I used Silas Max. Then, the 3 and 1 hybrid, then Silas liner over that the car is incredibly quiet . As far as sound dampening and deadening, it works very well for the money really can't beat it. Do your homework no How and where to apply it? And you really can't go wrong or about $400. I did. What would have cost me easily? Two thousand in other brands highly recommend the product prep work.Is everything do your homework?Do it right and you will be happy with this stuff
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Reviewed in the United States on May 6, 2026
★★★★★ 4
Not simple, nor easy
Model: SLH20025
I wanted to add sound proof material to the bare metal areas on the floor of my Toyota Tundra. The area behind the front seats had a haphazard application of sound deadening material. There were several complications to the project which may come up in other vehicles.
First is the floor covering which had plastic pillars underneath to support any weight on the cover. The sound deadening material had to be cut out so these pillars would rest on the bare metal of the floor. This required a lot of cutting with a utility knife and at times heavy scissors. The instructions say to make a template before cutting the material and I did this for the driver's side. This doubled the amount of time needed to install it. On the passenger's side I laid the rectangles of material with the backing on and pressed the floor covering onto the material. This showed where the support pillars were, which I then cut out.
Second is peeling the backing off the material. This can be very difficult as the adhesive sticks to it. The backing came off in multiple pieces and sometimes took 5 minutes for one piece. They say to wear gloves when handling the material but this is impossible when trying to get the backing off.
Third is pressing the material onto the metal. The instructions say to use a roller, but this was impossible for the irregular surface I was working on. The hand is the best tool to press the material on.
The material seems to be of high quality and I expect it will reduce the road noise in the cab.
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Reviewed in the United States on May 18, 2025
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