Yes these are detailed in the manual, which is available in the DOWNLOADS section at the bottom of this page

TPS components are interchangeable. In most instances we recommend a department purchase the TPS4 system, since this means that all features are available, but in busy departments, where multiple patients might be treated simultaneously, an additional TPS 2 or TPS3 might provide all that is additionally required.

The TPS is designed to fit exercise bikes and bicycles with a three piece, tapered crank. This refers to the centre axle of the bike. This is the axle that goes through the exercise bike, and to which the existing cranks are fitted. THE TPS MUST NOT BE FITTED TO SPINNING BIKES OR ANY BIKE [...]

The Therapeutic Pedal System is a range of products. The products offered range from a full function clinical model (TPS-4) to a home use version (Retroflex) designed for patients with chronic ROM problems who wish to exercise or ride a bicycle. The system you purchase can be tailored to your requirements.

The term Therapeutic Pedal System refers to the cranks (disks), the pedal adapters, the swing pedals, swing pedal journals, foot and heel straps, and mounting hardware. The TPS can be purchased without an exercise bike, or UniCam can supply the system fitted on one of a variety of exercise bikes.