MMdex Pipe Thermometer / Thermo Water Oil Temperature Gauge with Clip-on Spring, 0x2103; - 120x2103; Temp Range, Diameter 63mm / 2.48" Clip on spring pipe dial thermometer/ temperature gauge For connecting to outside of pipes. Stainless steel case. Spring for 20-60mm pipe diameter; Temperature Range: 0-120 Suitable for hot water, hvac, heating, oil tanks, etc Thermometer Diameter: Approx. 63mm/ 2.48"