Mega gridlock is designed for permanent pipe grid installations in studios and theaters. Joins 2 overlapping pipes together in a 90 degree joint. Grooves act as a wrench holding the nut from turning while installing. Installs with a hex key tool in a battery drill. The mega gridlock can be used on curved track down to a radius of 3 feet (or a circle with a diameter of 6 feet). Tighten the bolts to 11 foot pounds, which is about as tight as as can be done with a 6" hex key wrench.