Eltramarine Piston Ring Compressor, Item No PF1303-6". It is a specialized automotive hand tool used during engine assembly to compress piston rings for safe insertion into the cylinder block.
Capacity: 60mm to 195mm (approx. 2.36 inches to 7.68 inches).
Height: 6 inches (152.4 mm).
Material: Special spring steel.
Features: Ratchet type mechanism for easy adjustment and includes a hex spanner.