Grower's Choice digital lighting controller enables the grower to control up to 200 fixtures. It is compatible with all GC-315 CMH, GC- 630NS CMH, GC-1000 DE fixtures, & ROI Series LED grow lights. This dual-channel controller allows daisy chaining up to 100 fixtures per zone. Enabling complete control of your growing environment with timed on/off switching, sunrise/sunset, and precise temperature readings with dual thermal probes and thermal-threshold auto dim-shutdown for additional protection.