All replacement thermocouple probes can be supplied with either a spring-loaded or fixed mounting fitting. The fittings are stainless steel 304 with 1/2 inch NPT for mounting into walls, connector heads or thermowells. The spring-loaded (SL) units allow up to 3/4 inch of travel. The welded (W) units have the 1/2 inch NPT fitting brazed to the probe. All replacement units are supplied with one inch of bare leads.