Ruffneck Defender XT-311 and XT-312 explosion-proof heavy-duty thermostats are the smallest, lightest, and most durable thermostats available. Specifications Temperature range 36°F to 82°F (2°C to 28°C) Temperature differential 2.5 F° (1.5 C°) Net weight 2.1 lbs (0.95 kg) Switching Snap acting Conduit opening 3/4?.