I bought new ski goggles and they came with a spare low-light lens but no way to protect it from scratches or cracking in a bootbag or back pack. This model holds 1-2 lenses (depending on size) for most ski goggles. Mine are Zeal Lookouts which are a pretty standard size so most brands spare lenses should fit. After playing with hinges and latchs and being unsatified with how well those held up I switched to using rare earth magnest to hold the case together. I use 8mm (5/16) rare earth magnets from Harbour Freight.  I recomend printing in PTEG.