For External Halyard Flag Poles. Cap Style Stationary Single Pulley. Cast aluminum construction with a 1 in. outside diameter cast nylon pulley on a 3/16 in. stainless steel axle. Designed to slip over the top of the flagpole and be secured by one 1/4 in. - 20NC stainless steel set screw. The top of the truck is designed to accept an ornament with a spindle threading of 1/3 in. - 13NC as standard but can be supplied with other sizes of threading if desired. The ornament is secured to the truck with a size 10-32 stainless steel pan head screw. The recommended maximum halyard diameter is 1/4 in.