Bachmann HO Scale E-Z Mate(R) Mark II knuckle couplers have metal-coil springs on the knuckle of the coupler for extra reliability. They operate with their standard metal "glad hand" and an under-track magnet (sold separately). E-Z Mate Couplers feature positioned coupler heads and different shank lengths as noted, and are completely compatible with all magnetically operated knuckle couplers currently on the market. Centered shanks are most widely used on rolling stock. A variety of E-Z Mate couplers and accessories are available as replacements or enhancements to Bachmann freight cars, locomotives and passenger cars.