The TCP-150 includes a fast-change-lock for switching adapter types by only using one base unit. The top large RED button on the base activates the TCP-150 swivel function. The side small RED button is used to change out adapters. Adapters are available in: BT/CT HSK-A, HSK-E, HSK-F. Adapters can be swiveled in 45 degree increments and automatically lock into place.