This is a pair of the 3-3/4" - 4" Robart Foam 4 Wheel Inserts. FEATURES: For Robart straight and diamond tread wheels 3 3/4" (76 - 89mm) in diameter INCLUDES: Two Robart Foam 4 Wheel Inserts REQUIRES: Inserting between wheel and tire SPECS: Length: Approx. 10.6" (270mm) Diameter: Approx. 1" (25.4mm) COMMENTS: The header cards that come on some read 3"- 3-3/4". 3-3/4" - 4" is the correct measurement. rda 8/2/06 ir/jxs