The FR-4 is designed to fit the 20-spline tool fittings found on older SunTour® freewheels. Constructed from heat treated alloy tool steel, the FR-4 features a 1" tool fitting for use with an adjustable wrench, socket, or bench vise.
The ND-1 is designed to drive conventional slotted nipples onto spokes quickly and easily, making it a great time-saver and an essential tool for wheel building.