Home / Shotguns / Pro Lineup / S / Pro S4 (SEMIAUTOMATIC) Pro S4 (SEMIAUTOMATIC)$499 The Black Aces Pro S4. Starting at $499. 12 ga Shotgun Semi-Auto 5 +1 Capacity 3″ Chamber 18.5″ Barrel Wood Furniture Option Compatible with Benelli M4 Parts Pro S4 (SEMIAUTOMATIC) quantity Add to cart SKU: pro-s4 Categories: S, Semiautomatic, Shotguns Product ID: 1172 Additional information Additional information Gauge 12 Color Black Synthetic, FDE, Walnut Receiver Color Black Barrel Length 18.5" Related products Pro L (Lever Action) from: $399 Pro S Max (Semiautomatic) $409 Pro S (Semiautomatic) from: $449