... 2 Large roller 3 High-quality alloy steel 4 Top roller in U attachment 5 Automatic & CNC 1. ... etc.3. Material: high-quality alloy steel4 There are top rollers in the U attachment on the oterside link. ... Different kinds of attachments are available, such as top roller, K1, K2, A1, A2, extend-pin, etc. ... ensure delivery and lower prices. P125 roller chain with top roller in U attachment