Features: Open Circuit / Closed Circuit / Passive Semi-Closed Circuit planning ZH-L16 / VPM-B decompression models Convenient grouping of decompression stops Gas tracking of multiple gases and dive buddies Gas mixing through partial pressure and continuous blending Multiple graphs outlining dive profiles and tissue compartment pressures Select the version fitting your current level of diving, from Rec 1 to Unlimited CCR. More information at www.gue.com/store/software/decoplanner-4