Grounded thermocouple . The K type sensor probe can work well with PID temperaure controller Water proof Insulation Lead , water tight temperature sensor probe , rustproof with stainless steel material Measuring temperature range 0~500? . Accuracy : 0.2 . Cable: 78.7 inch ( 2m ) metal braided line . The wire is made of shielded glass fiber wire ,thr wire can withstand 600? high temperature . It is compesation wire with shield feature . Much better than Teflon . Probe tube diameter is 5mm ( 0.197 inch ) , length is 5cm (1.97 inch ) Features: Element:K Type Thermocouple Temperature rang: 0~500? Thread: NPT 3/4" (BSPT 1/2") Material: stainless steel 304 Protection tube length:50mm/1.97" , Waterproof Wire/cable Length: 2m/78.7 inch , Shield Accuracy: A grade 100% brand new and high quality. Terminal contact: 2-wire How to use : Connect the red fork to the + positive pole , and the blue ones are for "-" negative pole Package inclued: 1 x K Type Thermocouple