The B1 Binocular Adapter was designed to be the sleekest digiscoping system available on the market. No longer do you have to make the choice between stomping around your spotting scope to film or leaving it behind but missing the opportunity to capture footage at a distance. - Impossibly small yet impressively strong the B1 Adapter seamlessly integrates with your binocular of choice. Slip it onto the eyecup and tighten the retaining screw. That's it. A set it and forget it design does not impede normal use of the binocular making this tool an efficient and practical addition to your kit. Together with the MAGVIEW Phone Plate this system creates the ultimate light and fast digiscoping platform for steady sharp photo and video every time. - B1 XL- Fits eyepiece sizes 44mm-48mm (1.73in-1.89in) - Includes: B1 x1 MAGVIEW Phone Plate - Made in the USA.