Premium Material and Good ConductivityHigh-current collector rail with reinforced fireproof ABS base, fiberglass reinforced nylon base to ensure excellent mechanical strength and durability; Stainless steel nuts and bolts for improved performance in salt water or corrosive environments. Excellent corrosion resistance and rust resistance; the distributor block bus box is made of tin-plated pure electric copper, and the maximum current is brass tape. 2 HP 4 x M8 screwed bus barsThey have high performance track rails with 4 x M8 screws, they have many connection points for red positive and black negative, with 5/16 inch holes, modular box design, removable for easy wiring configuration [Construction Principle] The black car distributor is connected to the negative pole and the red to the positive pole; the rated current of each screw is 62.5A, the rated current of the entire electric block is 250A; the current of the auxiliary terminal screw is 20A. The maximum voltage is 48 V DC Wide application: the connection rail is suitable for power supply systems such as motorhomes, solar panels, cars, trucks, yachts, boats etc. Whether you need to consolidate, distribute or protect your electrical system, DC track rails can join all wiring harnesses together and store cables properly in vehicles and boats Live well on chaos - With these power distribution blocks, you can finally organise your wiring so that it does not feel like a messy pile of lint under the hood. Keep all energy systems organised Case back material: nylon, fibreglass reinforced. Maximum operating voltage | DC 48V Maximum continuous current | 250 A Post size | 4 x M8 (5/16 inches). Dimensions (L x W x H): 19 x 4.5 x 5.6 cm. Package includes:2 x Red/Black Pair M8 Bolt Set (Including the connection terminal accessory in the main picture)