Grundfos Timer Control For UP15-18SU Pump # 505474 (B)The Grundfos 50574 Timer Control only fits the UP15-18SU circulator pump. May be used alone or with a Aquastat control.Switch modes include "Timer" for normal programmed operation and "On" and "OFF" overrides for manual operation. Clear plastic cover protects the clock face from dust and < Simple 24 hour programming is in 15 minute ON/OFF increments. 505474List: $93.00Discounted Price $70.00 Grundfos 1/2" Clip-on Aquastat Control 115 volts #595443 (B)Automatically turns the circulator "OFF" when the line temperature exceeds 105 degrees F. and "ON" when it falls below 85 degrees. Clip-on mount for 1/2" I.D. copper tubing 595443List: $36.00Discounted Price $27.00 Grundfos 3/4" Clip-on Aquastat Control 115 volts # 595444 (B)Automatically turns the circulator "OFF" when the line temperature exceeds 105 degrees F. and "ON" when it falls below 85 degrees. Clip-on mount for 3/4" I.D. copper tubing 595444List: $36.00Discounted Price $27.00