ARP 4.2125 in. Ring Compressor

Designed for installing piston rings on engines with a 4.2125 in. ring diameter, this ARP ring compressor delivers controlled, even compression to ease piston assembly and reduce risk of ring damage. The tool's precise sizing makes it suitable for repeatable, accurate installations where consistent ring alignment and smooth piston entry are required, helping professional engine builders and DIY enthusiasts complete assemblies faster and cleaner.

Features:

• Diameter 4.2125 in for piston rings