A typical system is made up of a set of bells, a programmable transmitter, a stand-alone keypad, an antenna with a magnetic base, two connection cables, and a set of service manuals. Each choker is programmed with one of 256 release codes at the time of manufacture; the release code is stamped on each bell. The transmitter installed in the yarder can be programmed to release up to nine chokers, either simultaneously or individually. Once programmed, the operator need only use the stand-alone keypad to open the bells. Accessories also included are a puller-tool for accessing the choker's battery, and a hand-held short-range transmitter to operate/test bells prior to returning them to service.