Bi-metal, industrial type head and stem are 304 stainless steel. Head may be adjusted for viewing at any angle and tilted over a 180° arc. 5" face with 2-1/2" stem, 1/2" NPT connections. Easy to calibrate by inserting allen wrench into reset opening. Stem diameter 1/4". Extra-heavy glass crystal. Tel-Tru Manufacturing AA-575R (*Not recommended to continuous use above 800 F).