Topcon Remote Control for TP-L4/TP-L5 Pipe Laser Levels (329590002 ) 
Model Number: RC-200 
Features:
  Made of durable plastic
  Works with the TP-L4 and TP-L5 series pipe laser levels
  Power Source: (4) AAA alkaline batteries
  Range: Front: 660 ft. (200 m); Rear: 82 ft. (25 m)
  Auto centering
  Laser standby to save battery power
  Beam mode to manage brightness
  Slope match for quick grade reference and elevation matching