Enlighten II Mask:Tempered glass meets all ANSI standards; PVC skirt & strap provides a comfortable fit; Easy-adjust strap with quick side release buttons; Pivot buckle adjusts up and down for fitMoana Snorkel:Purge valve for easy clearing of excess water in snorkel; Submersible dry top seals to prevent water from entering; Quick release mask strap clip on tracking system to easily adjust up & down; Pre-bent flex section for comfort