Frameless I is medium-fit design and super low volume mask with single tempered safety glass lens frameless design. Classic Soft Crystal Silicone Skirt - The mask material is extremely comfortable to wear with Double-Edged Facial Seal Technology. Swivel Buckle Design - Our mask has an unlimited range of motion that achieves perfect adjustment on the mask. Soft Silicon Nose Pocket - This feature prevents ear clogging when divers get into deep water. It equalizes the internal ears’ pressure by simply pinching your nose shut, inhaling a mouth full of air and closing your mouth.