This is the 8x1.0mm Double Jam Nut Adapter Kit from Tru-Turn.
FEATURES: Steel construction.
The screw is tapped 10-32 for cone screw.
Used to mount Tru-Turn aluminum spinners onto the following engines:
YS .90, 1.20, 1.40 4-Stroke Engines
INCLUDES: One Adapter Nut
One Adapter Jam Nut
One Propeller Washer
One Aluminum Bushing
REQUIRES: 1/2" End Wrench To Tighten
Tru Turn Aluminum Spinner
SPECS: Crankshaft Thread Size: 8 x 1.0mm
Spinner Mounting Bolt Thread Size: 10-32
Bushing Size: Inner: 8mm Outer: 3/8"
COMMENTS: Will Not Fit Smaller Than 2-1/2", Too Small.