The Apeks XL4 is especially well-suited for the technical exploration diver who prefers cold water climates. Compact and lightweight, it helps reduce jaw fatigue during long, cold dives. Designed with an innovative, over-moulded endcap in conjunction with the environmental diaphragm that helps prevent ice build-up. The XL4 makes an ideal stage regulator and is also an excellent high-performance option for the technical exploration diver who is serious about maximizing functionality and minimizing weight.