The boom spacer provides support for plug-on transmitters that connect via a side-exit 90 degree mount. Most crucially, when the boom pole is inside a boom box, this keeps the plug-on transmitter from bending towards the pole and causing hardware failure at the XLR connection point. 

Simply snap it onto the pole and position the pad facing the transmitter. Place the rounded side facing down so your hand can easily glide over it when moving up the pole. 

These are made with highly durable and weather/UV-resistant ASA filament. They also include soft TPU 95A on the outside to gently cushion the transmitter and on the inside to better grip the pole. 

Limited availability on-hand. Be sure to provide pole and transmitter specifications upon ordering. Certain pole and transmitter models may need measuring first.