These are the Piston Pin Retainers for the O.S. GT55 Gasoline Airplane Engine (OSMG1555). FEATURES: Steel construction Replaces worn or damaged piston pin retainers INCLUDES: Two piston pin retainers REQUIRES: Installation on either side of piston pin SPECS: Height: 1.65" (42mm) Diameter: 1.62" (41mm) COMMENTS: For the Piston Pin order OSMG7770 For the Piston Ring order OSMG7843 For the Connecting Rod order OSMG4035 For the Cylinder Liner order OSMG5400 lmm 04.13.10 ir/jxs