This adapter is typically used to join two pieces of photography equipment which have different sized 14 and 38 female mounts it can used with a variety of equipment and accessories such as flash units studio lights tripods flash brackets etc connector male x 114 inch nominal diameter 20 threads per inch unified thread standard connector male x 138 inch nominal diameter 16 threads per inch unified thread standard this adapter has a 14 screw on one end and 38 screw on th