- Mark 4 split lenses are flat and distortion free. The soft sheepskin face cushion fits your face and keeps out the wind. The width of the lenses adjusts for a perfect fit and vents prevent fogging. The Mark 4 goggle has a clear lens.
- The 510 goggle has curved laminated lenses that permit a wide field of vision. They are lined with sheepskin to comfortably fit your face. The fabric-encased, coil-spring strap fits snugly. The type 510 goggle has a clear lens.