The TMC Modules are available in both 4 station and 8 station expansion sizes. The TSM-4 and TMS-8 are standard modules appropriate for either the indoor or outdoor TMC-424 model controllers.

The TSM-4H and TSM-8H are High Surge modules designed to withstand higher electrical surges than standard models and are appropriate for either the indoor or outdoor TMC-424 models. High Surge modules were developed to increase reliability in high lightning areas, where nearby lightning strikes often cause surge damage to controllers. High Surge modules will help protect from surges entering from ground wiring in yard, but will not prevent surges from entering controller from power source.

The TSM-4F and TSM-8H are High Surge and Flow Metering modules designed to resist higher electrical surges and to be compatible with up to 3 Flow Sensors simultaneously. The TSM-4F and TSM-8F are both compatible with both indoor and outdoor models of the TMC-424 controllers.