Aqua Lung Axiom Men Scuba Diving BCD Dive Light Accessories With its patented ultra freeze resistant Extended 216841 04 A With its patented ultra freeze resistant Extended Thermal Insulating System (XTIS) the MK25 EVO offers excellent thermal insulation by fully isolating the mechanical elements of the first stage from the cold A generous lens shape gives the low volume single pull weight release with patented SureLock II Mechanical Weight Release SystemAdditional Dump Option Right shoulder pullOral Inflator Easy to use pull down oral inflatorBladder Retraction System Bladder retraction system pulls in the sides of the bladder during deflation to keep you streamlined and reduce dragSmooth If you want the perfect comfort