This document is the user manual for Serious Divers® CO8000 NiTek Q Computer. It describes the functions and displays of the computer and provides important warnings and cautions before diving. The computer is an electronic device and it is essential to fully understand its functions and displays and be proficient in their use before diving. Diving with the computer without a backup device or dive tables is not recommended. Proper training and certification are required before using the NiTek Q with Enriched Air Nitrox (EANx), Trimix, or closed circuit rebreather diving. The NiTek Q is not intended for commercial or military divers.