The i4 has a revolutionary patent pending rapid lens changing system that allows you to change lenses in under 10 seconds. The i4 offers more vertical and horizontal peripheral vision than any other mask system on the market today. Designed with the Professional in mind, the i4 goggle system provides you comfort, rigidity and lightweight protection with our one piece, dual injected mask. The sleek, light, low profile soft compression ear pads provide the protection you need while offering style and hearing clarity. The anatomically correct i4 mask system offers the best in comfort for all facial contours. The i4 retention strap system needs to be adjusted once and once only. One of the i4s greatest features is the Multi-Directional Venting.