Close focusing: observation : near landscape can see both far and near, suitable for bird watching, hunting, hiking, camping, sightseeing, Stretchable : freely stretchable , fun and interesting, so many lovers canot put it down, small, light and portable Blue film: it can high light-transmittance and low reflectivity to increase light-transmittance and a clear and bright field of view Bqk4 lens: lens, exit-pupil is a round light spots, the light-transmittance is very high, clear and bright All-metal frame: all-metal frame, fashionable and beautiful