Profile Imperial sprockets are CNC machined from 6061 Aluminum made in the USA. The Imperial is “bolt on” style and requires a sprocket bolt to be attached to crank arm.
All Profile Imperial chainwheels have a .875" spindle hole with adapter to fit 0.75" spindles - they do not fit 1 or 2-piece cranks
For use with 19mm spindles only
3/32” teeth for 3/32” and 1/8” chains