Thanks to PeterW for printing these adaptors. Based on a single measurement from me (outside diameter of the objective housing), these fit very well with a few bits of insulating tape around the inside to take up a small bit of slack. I am in the process of cheekily asking for a small mod to be made, and for a reprint in black but that may well cost me a beer or two . The filters themselves are held very snuggly against the binos, no rattling around. I bought the binos off eBay relativ