The cranks attach to the spindle via a common square taper, cotter or splined interface. Power is transferred by an enclosed splined driveshaft with one universal joint. The rear wheels were driven by splined half-shafts. The end of the driveshaft is splined and fits into the outer "joint". The tripod is splined to the intermediate shaft and held by a circlip. Transmissions end with a splined tail shaft, more commonly called an "output shaft". Head designs that overlap both are the Allen or Torx heads; hexagonal or splined sockets. Disc brake mounting interfaces that are splined include Centerlock, by Shimano. Phil Wood uses a similar splined design to the Shimano bottom bracket. Steering is by worm and complete wheel with a taper and splined drop-arm connection. Their second feature was that they were easily detachable being mounted on splined false hubs. GKN had designed a bolt that had a splined section above the nut. Shimano introduced a proprietary splined interface named "Octalink". Depending on the construction, the end of hub comes equipped with the splined teeth. Several different competing standards for splined interfaces exist.