Baby got back. No, we're not talking ba-donk-a-donk; we're talking stud backers. Lightweight, plastic stud backers. We made these 1-1/4" round to stop track tearing. These backers are 0.140" thick, and 1/2" tall, the perfect weight and profile to secure most 5/16" diameter studs. 100% nylon construction for outstanding performance and impressive durability. Extreme Max Round Plastic Backers are not compatible with Extreme Max .875" Snowmobile Studs.