Optex full-featured 100' Dual Photoelectric Beam. The industry's most full-featured short range photobeams. 'Finger-Touch' alignment controls and precise beam definition combine with gun-sights and voltage meter jacks to make installation easy. A weatherproof (IP55) housing applies rubber ''O'' rings to keep out insects and dirt. Lightning protection exceeding 14kV, form C relay. Optional heaters and back covers are available.