50 years ago all masks looked like this classic mask from IST. The design of the IST M27 Tortuga Traditional Oval Single Lens Mask may give the impression that time has stood still, but IST has implemented decades of engineering advances into this classic, retro-style mask to bring it into the modern age. The Tortuga features a tough, tempered glass lens for maximum clarity and safety. A liquid-injected silicone skirt and strap and rugged, modern metal band on the mask frame are improvements built to stand the test of time on a mask that will never go out of style. A basic design to fit a majority of faces makes Tortuga a great back-up mask for the occasional guest or diver who forgot his or her own mask, or for the diver with a moustache. Tortuga offers a super-easy equalization feature: simply place your index finger in either hose well and press against your nostril while blowing lightly through your nose. The classic lives on – Tortuga!