The original Connect Quick that will allow fast attachment of a horizontal tube to a vertical tube for antenna mounting, sound equipment installation, solar panel mounts etc. The plates are aluminum, the bolts are stainless steel and the spring plunger assembly is tool steel plated with copper and then nickel. You supply the u-bolts and nuts in the appropriate sizes for your application. The plates will allow for sizes from 3/4" to 2" diameter. Retail $34.95