Surface Treatment: galvanized, black, antique copper, nickel, copper-head types: the first, Shen Ping, in the first half Park, the first park, the flat, with edge, with the type of flower trough: word slots, cross-slot , The composite slot, with 1.6, 1.6 outside the compound outside the hexagonal slot, Jack slot, to the word thread tooth-slot: Germany, the United States, Japan, Britain, the metric system, will be locked tight, self-locking, solid-resistant, drop-resistant, and so on