GP876851 Mixer Cap and GP800820 Pressure Balancing Cartridge Unit Kit Critical Installation 1. Please clean internal impurities with sandpaper before installation 2. O-ring is the key, must be replaced, then firmly placed in the correct position. 3. Do not rotate the Cartridge, just put it in, otherwise the O-ring will shift and cause leakage. 4. Tighten the screws to fix the cap and the Cartridge. Features: Control pressure adjust temperature solving leakage and dripping Material: Plastic and Brass Color: Black GP876851 Package includes: 1×GP77759 Mixer Cap 1×GP500520 Pressure Balancing Unit