Features: Make of aluminum Alloys materials, light weight, strong and enduring.
Easy to install, and can use 3/8inch wrenches(excluding) to install the crankshaft screw.
This product is used to fix the crank and crank of the sprocket.
It is suitable for mountain bikes and road bikes.
Standard thread, fit perfectly to keep water, dust and others out.

Specifications: Materials: Aluminum Alloys
Style: 18mm/19mm/20mm
18mm size: about 18x12mm/0.71x0.47inch
19mm size: about 19x12mm/0.75x0.47inch
18/19/20mm size: about 20x12mm/0.79x0.47inch

Package Includes: 1Pc Crank Arm Screws

note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.