This unit is designed for 5" diameter poles and is used with rope style internal halyard systems. Each unit consists of a hinged door mounted to the front of the frame and a cam cleat (optional) mounted to the back of the frame. The entire unit is inserted into the flagpole shaft and secured with eight 1/4"-20NC stainless steel screws. Minimum hole opening 5-1/2" x 3-1/4". Lock & keys included. Standard colors are Silver, or painted to match Clear, Bronze, White or Black. Please specify color when ordering. If not specified Silver will be supplied.