The small PTC bead is protected with epoxy resin and a shrink sleeve. The sensing head is only 4mm max. diameter and gives a fast thermal response of less than 5 seconds. The standard version has 200mm long 26AWG PTFE leads with longer leads, triplet versions (to DIN 44082) and various mounting options also available.
Although primarily designed for electric motor protection, these small PTC sensors offer a very neat solution to numerous electrical and electronic circuits that require a simple step-function response to an over-temperature condition.