DA-4030-A by Midland | Cam and Groove | Type D | Reducer Coupler | 4" Female Coupler x 3" | Adapter | AluminumCrossover Series: DA XXX A Part Number Female Coupler x Male Adapter DA 1510 A 1 1 2" x 1" DA 1520 A 1 1 2" x 2" DA 2015 A 2" x 1 1 2" DA 2030 A 2" x 3" DA 2040 A 2" x 4" DA 3015 A 3" x 1 1 2" DA 3020 A 3" x 2" DA 3040 A 3" x 4" DA 4020 A 4" x 2" DA 4030 A 4" x 3" DA 4060 A 4" x 6" DA 6040 A 6" x 4"