The Mares Puck 4 dive computer is a compact, reliable tool for scuba and diving sessions. It uses the Bühlmann ZH-L16C algorithm with adjustable gradient factors to tailor gas management and decompression safety. It supports air and nitrox (EAN 21%–99%) and includes a bottom timer mode for depth tracking during dives.

With a maximum depth of 150 m (492 ft) and logbook capacity of up to 100 dives, the Puck 4 records data for later review. It features a clear segment display based on chip-on-glass technology with 800 segments for crisp readings, and a mineral glass display for durability. A user-replaceable CR2450 battery provides up to 100 dives of life. Integrated Bluetooth enables direct connection to the Mares or SSI app for logbooks, plan updates, and firmware upgrades. The design includes intuitive single-button operation and removable straps, including a bungee option, for comfortable wear on long dives.