The FR-3 is made from heat treated alloy tool steel, one inch base fits wrench or bench vice.
One-inch base fits end of SR-1, FRW-1 Park tools or simply an adjustable wrench / spanner or bench vice
Fits Suntour four notch freewheels
Note: You will also need a chain whip tool to hold the cog in place.
Weight: 58g (2.ozs)
Park Tool Reference: FR-3