This is the Great Planes ElectriFly Power System Brushless Motor Mount. This attaches to the firewall and the electric motor attaches to this mount. FEATURES: Direct replacement for the Great Planes GPMG1041 .20-.48 (3.3-7.9cc) and GPMG1061 .40-.70 (6-11cc) glow mounts Perfect fit for both 35mm RimFire Out-runner 28mm Ammo In-runner motors Universal motor mounting bolt pattern insures an easy fit with many brands of motors Lightweight aluminum construction for added durability Unlimited adjustability from 2.1 - 3.1" (56 - 78mm) For medium motors INCLUDES: One motor support for medium motors All assembly hardware REQUIRES: Mounting to the firewall and attaching the motor SPECS: Length: 2.53" (64mm) Width: 2.18" (55mm) Height: 2.18" (55mm) Weight: 2.3oz (81g) Mounting hole dimensions: 1.325" x 1.325" (33.65 x 33.65mm) rmb 12-20-06 ir/jxs updt jxs 02/29/12