Direct factory supply of waterproof nuts, sealed nuts, and rivet nuts in sizes BS-M3-1/2, BS-M4-1/2, BS-M5-1/2, BS-M6-1/2, B-M3-1/2, B-M4-1/2, B-M5-1/2, B-M6-1/2, etc. 1. Rivet nuts (S, CLS, SP, CLA, B, BS), 2. Insert nuts (F), 3. Expansion rivet nuts (Z, ZS, NZ, NZS), 4. Self-locking nuts (U, U)