You can attach this item without opening the chest belt of the harness. There is an excellent pressure dispersing function. Waterproof external material. OKO -TEX material, with a breathable inner lining. Reflective edge protection. The cushion lines both straps of the harness on the dogs chest. Manufactures using German raw materials. This product is tested by recognized and respected dog trainers. The chest pad can be used on all Julius-K9 Harnesses