The Sprue brand Scaleauto are formed by two distinct parts.
The first acts as a kind of brass collar that is fixed to the shaft by means of a screw M2 and count as a slot to permit "fitting" of the motor axle on the rack.
The second, which is the sprue itself without the "fit" to the motor shaft, is also fixed to the axle by a screw with hexagon size M2.
This separation allows you to use different diameters of sprockets or else tune best distance between the motor shaft and the rack.
Allowing the contact surface and the pressure exerted between the two is set for the best performances.
Type: In line
Material dentition: Nylon
Set Screw: M2
Axle: 2.38mm (3/32)
Diameter: Ø 13.1