This is a Dave Brown Glass filled nylon engine mount for .049-.051 engines. FEATURES: Glass filled nylon construction. INCLUDES: One nylon mount. Four sheet metal screws to attach engine to mount. REQUIRES: Mounting screws and blind nuts to attach to firewall. SPECS: Length of arms: 22.5mm (.886") Inside distance between arms: 17mm (.673") Outside distance between arms: 28.2mm (1.112") Overall length: 29.1mm (1.148") Thickness of arms: 10.0mm (.394") pjm 7/19/02 ir/kh