The Mark 410 model is one of the highest quality Halcyon googles available. The brass frame is polished to a mirror finish before being chrome plated. It is then hand stitched to a soft leather face mask. The nose bridge screw is now manufactured using a quality stainless steel this is to add more strength to the thread and is one of the few changes that have made to the goggle over the last 30 years . The curved lenses are made from a good quality polycarbonate that is treated with a scratch resistant coating to prevent damage to the surface. Each lens is housed in an independent frame that can be easily removed from the goggle to allow replacements to be fitted. Also comes with triple silicon non-slip strips fitted on an elasticated head band for the perfect grip when worn over an open face crash helmet.