This weldless thermowell is made from solid 304 stainless. It has a straight ½” BSP thread which is 40mm Long. It includes silicone o-ring, stainless steel slimline nut and also the extra long nut for mounting directly to our 3 inch dial thermometers. This thermowell can also be used in conjunction with temperature controller probes, the probe will fit straight into the thermowell.