Cal-Van Tools Piston Ring Compressor Set includes a seven(7) piece set that installs piston rings from 2-7/8 inch to 4-3/8 inch (73 millimeter to 111 millimeter). It works both vertically and horizontally. The set includes fine tooth ratcheting pliers for accurate compression and 6 interchangeable bands. The interchangeable bands are as follows: no. 641-1 band size 2-7/8 inch to 3-1/8 inch; no. 641-2 band size 3-1/8 inch to 3-3/8 inch; no. 641-3 band size 3-3/8 inch to 3-5/8 inch; no. 641-4 band size 3-5/8 inch to 3-7/8 inch; no. 641-5 band size 3-7/8 inch to 4-1/8 inch; no. 641-6 band size 4-1/8 inch to 4-3/8 inch.