Nitro RC Roto or Electric start backplate. Universal fit for most engines with larger backplates, but if in doubt please ask.
Insert for 1 x 12mm Hex one way bearing fitting (Bearing not included. See Ebay item number 283850431766 for the correct bearing)
38mm Length (Across Backplate)
38mm High (Across Backplate)
30mm between fixing hole centres. Measured both vertically and horizontally
19mm Depth / Width
The screws supplied will suit many engines. they may need to be cut to size.
From my experience this pull start will fit the following engines. it may also fit others.
HPI Nitro Star engines
Thunder Tiger engines