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 1.20-1.80 cu in (20-30cc) glow mount
• Perfect fit for 63mm RimFire Outrunner 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) 

Includes:

• One motor support for extra large motors
• All assembly hardware

Requirements:

• Mounting to the firewall and attaching the motor

Specifications:

• Length: adjustable from 3.5-4.6 (89-117mm)
• Mounting Plate Width: 3.1 (79.5mm)
• Mounting Plate Height: 2.4 (62mm)
• Bolt Pattern: 1.94 (49.3mm) at mounting hole centers