Accuracy is ±1% full-scale when stem is immersed 2" in liquids or 4" in gases (immerse models with a 2.5" stem length 2" in gases). Measured stem length from the top of the threads to the bottom tip of the stem. Stem dia is 0.25"; threaded connection is 1/2" NPT(M). All thermometers meet or exceed ASME B40.3 standards. Maximum environmental temperature for glass lens thermometers is 500degF (148degC). Discounts: Save 10% on 10-24 assorted thermometers, 15% on 25 to 49, and 20% on 50 or more.