This is the Cover Plate for the .18CV-R(P) OSMG2100 & .18CV-R OSMG2101 / / FEATURES: Cast and machined natural aluminum construction / / INCLUDES: One cover plate (aka: back plate) / / REQUIRES: Gasket set OSMG6037 / Screw set OSMG8646 / / SPECS: Length: 12.5mm / Width: 25.1mm / Height: 25.1mm / Distance between mounting hole centers 18mm top to bottom, L to R / / tjt 050504 / ir/jxs