The JBJ True Temp Magnetic Heater Holder is a replacement heater holder for the JBJ True Temp Titanium Heating Systems. It is also can be used as a safety guard and magnet holder for heaters from other manufacturers. Magnet holders are far more reliable than the suction cup holders that come with most heaters. The four magnets will hold the heater firmly to the tank in two places. The holder can handle heaters up to 16" in length and 1" diameter. This will accommodate the Hydor Theo, Ebo Jager and Eheim aquarium heaters. The heater holder comes in two sections and you can just use the 9" section for shorter heaters. The safety guard will prevent against heater breakage caused by large, aggressive fish.