Features: PYROFLEX™ IR sensor and HighBar™ signal processing for superior performance. 2 (two) 60 pound Pet Immunity; up to 85 pounds. 44 foot range and 90 degree field of view (45 degrees to each side). Mountable on Flat-wall, 45 degree corner, or swivel/gimbal (sold separately). Walk test LED. ***Unique external contact on separate wireless ID*** 6-8 year battery life on 1-CR123 Lithium battery. Cover tamper. Low Battery indication. Strong, reliable RF signal. 2.5 x 4.5 x 2 inches.