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 GPMG1091 .60-1.20            
            (10-20cc) glow mount                                               
          Perfect fit for both 50mm RimFire Outrunner and 36mm 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 3.5-4.6" (89-117mm)                     
          For large motors                                                     
                                                                               
INCLUDES: One motor support for large motors                                   
          All assembly hardware                                                
                                                                               
REQUIRES: Mounting to the firewall and attaching the motor                     
                                                                               
SPECS:    Length: adjustable from 3.5-4.6" (89-117mm)                          
          Mounting Plate Width:  2.7" (68.5mm)                                 
          Mounting Plate Height: 2.17" (55.1mm)                                
          Weight: 4.9oz (140g)                                                 
          Bolt Pattern: 1.85" (46.9mm) at mounting hole centers                
                                                                               
                                                                   rmb 12-20-06