Norman #1/2-INSERT, 1/2" Bushing Insert Converts the R4108 Umbrella Stand Adapter or R4130 Friction-Float Swivel Bracket from 3/8" to 1/2". Norman #1/2-INSERT, 1/2&quot; Bushing Insert Converts the R4108 Umbrella Stand Adapter or R4130 Friction-Float Swivel Bracket from 3/8&quot; to 1/2&quot;.