This is the premium version of our Model 520 Calibrator. The 521 includes simulation of thermocouple types J, K, E, T, R, S, B, N and mV. Higher resolution gives more precision in the setpoints. Given its capability, performance and amazing simplicity; you'll be impressed by the value you get at this price. Quickly dial-in any temperature in 0.1° increments using the digital dial. Press the knob as you turn and you get even faster dialing to cover larger changes in settings. Easily beats the complexity and slowness of other digital calibrators. You'll get to your precise setting faster with no diddling around. There's no complicated programming or tedious manual-reading. The EZ-Check function stores three temperatures of your choice for instant recall. Use these for fast checking of zero and span or any critical temperatures that are used repeatedly. Each unit is fitted with a common mini-jack. Coiled connecting cables are available separately or use your own cables. A factory certificate of compliance is shipped with each unit. An optional traceable certificate may be ordered with actual test data.