Watlow's 375 finned strip heaters are constructed of highly-compacted MgO-based insulation, which conducts heat efficiently from the nickel chromium element wire to the sheath. Two-inch wide (51 mm) aluminized steel fins are attached in a way that maximizes surface contact so heat is transferred into the air faster. Lower sheath temperature and element life are all maximized by this finned construction. Finned strip heaters com in available lengths from 5 1⁄2 to 48 in. (140 to 1220 mm).