These bar pile holders are made on 1" round on two 1-1/2" x 5" x 1/4" plates. Slip it over your existing piling and bolt to your dock or bolt to your dock, then install the piling (recommended). Sizing note: Always use the next size larger hoop. For example: if you have a 8" ID piling, use a 10" hoop. All steel components are hot dipped galvanized.