Using polymer ABS material, the inside is copper core, sealing ring, copper core thread is clear and firm, leak-proof and dust-proof design. package: 4 pcs Notes: 1. Due to the difference between different monitors, the picture may not reflect the actual color of the item. We guarantee the style is the same as shown in the pictures. 2. Due to the manual measurement and different measurement methods, please allow 1-3cm deviation. Thanks!