Tesla Copper Immersion Heater - 30 inch Element Boss: 2.1/4" Element Length: 30" Thermostats: High Limit & Control Element Material: Copper * Not Suitable for Stainless Steel Cylinders * Suitable for soft watwer areas *Available in 11, 14, 18, 23, 27, 30 & 36" Length Immersion heaters are manufactured and approved to EN 60335-2-73. All Immersion Heaters are supplied with a dual safety thermostat, instructions and sealing washer.