This is a 1" wide by 8" long strip of Yokomo "Thin" Dust Filter Magic Tape. This hook & loop type of dust-proof velcro is backed by double-sided tape and works great for attaching the body to your vehicle. Because the double-sided tape is heat-resistant, this tape also works great for attaching the receiver and transponder to the chassis.
This tape is very similar to the Yokomo ZC-105, but is thinner at about 1mm thick, with both hook & loop pieces attached together.