These wedge-shaped components slide in for a snug, stable fit. The type B seat mounts are designed to "lock" into the post. Heavy-duty bushing with peripheral bearing system is sized for exact fit. 2-3/8" dia. posts feature a satin-anodized finish. Power pedestals include integral seat mount. Strong base plate has reinforcing ribs to withstand tough conditions. 2-3/8" dia. Adjusts from 24" to 30" high.