1 x 0GA IN/ 2 x 4GA OUT - Make wiring your system easier with high quality distribution blocks from DS18. NICKLE PLATED INTERNAL MATERIALS - Eliminates the possibility of corrosion, rust, oxidation, or premature wear on speaker wire connection points. Ensures you get the longevity out of your system that you expect. HIGH CONDUCTIVITY COPPER ALLOY - All of DS18's distribution blocks are made with high conductivity copper alloy and chrome plated to maximize the security of your connections. Ensure your wiring is secure, neat, and safe. OVERSIZED SET SCREWS - Allen head tops and oversized set screws with small serrated ends guarantee a strong consistent connection that instils confince against loose wires. DEEP WIRE RECESSES - DS18 has designed these distribution blocks with deep recesses to protect your wiring from being left exposed to the elements or other objects that might cause your system to malfuction.