I've been using this for about six months, and there are no noticeable scratches or stains, and the light output hasn't degraded at all. See here for details: https://www.cateye.com/jp/products/headlights/HL-EL160/ Black LED light for bicycles, can be mounted on the handlebar. - Uses 2 AA batteries (not included for safety) - Mounting method: Handlebar mount - Lens type: LED lens - 1700 candela - JIS C9502 - Waterproof performance: IPX7 - Battery indicator shows remaining battery life (the headlight maintains brightness for about 30 minutes even after the indicator turns red) - 2 modes: steady and flashing - Mode memory function starts in the mode it was in when turned off - Replaceable bracket spacer - Includes a Flex Tight™ bracket for quick and secure attachment - Awarded the 2021 Good Design Award Thank you for looking.