The City Theatrical 138 Tee Slot with Integral Split Coupler is the receiving part of the Moving Light Hanger System. The Tee Slot works in conjunction with the Tee Head to hang a moving light in the same place each time. The 138 Tee Slot is built on a Integral Split Coupler for mounting the Slot on a pipe. The Tee Head settles into a groove in the Tee Slot to temporarily hold the head in place even when the Tee Head knob isn't tightened.