3M™ Thinsulate™ Acoustic Insulation SM400L

Yes, Second Skin Audio is an official retailer of genuine 3M™ Thinsulate™ Acoustic Insulation. As an approved 3M™ Preferred Converter, we source our inventory directly from the manufacturer to supply top-tier, authentic SM400L and SM600L materials for your car, truck, or camper van conversion. Buying from us guarantees you are getting the real deal, fully backed by 3M's premium thermal and acoustic technology.

A full roll of SM400L Thinsulate measures 375 linear feet by 60" wide, with a 42" diameter as shipped from the factory. If you need a full roll of Thinsulate, reach out to us for a quote!

Use heavy duty tailor fabric scissors, an electric fabric cutter, or a rotary cutter with a T-square. Don't use a utility knife. Cut Thinsulate to a size that still allows the upholstery or trim panel to be reinstalled.

The white web side takes the adhesive and bonds to the substrate. The black scrim side faces out, toward the vehicle's interior.

Not waterproof, but hydrophobic. Thinsulate resists absorbing water, and any moisture that reaches it wicks through the material rather than saturating it.

Either works for most vehicle insulation jobs. SM600L is preferred where there's enough space for it, since the extra thickness delivers a higher R-value. Typical uses for each:

• SM400L: van door panels, headliners, wheel wells, pillars, and wall panels. Semi truck door panels, headliners, and sleeper cab walls and roof. RV wall panels, roof panels, and door panels. Skoolie headliners and wall panels. Car headliners and doors.
• SM600L (preferred where space allows): van door panels, headliners, wheel wells, pillars, and wall panels. Semi truck door panels, headliners, and sleeper cab walls and roof. RV wall panels, roof panels, and door panels. Skoolie headliners and wall panels.