The 2-1/2" Aluminum Nail is designed for use with sprinkler irrigated Har-Tru clay courts. This nail features a 7/16" diameter textured flat head and is the best option for most Har-Tru courts, especially those with shell and lime rock screening bases. The 2-1/2" aluminum nail is sold in a 9 lb. box that provides enough nails to install one set of line tapes.