1p78瞄具的,外网搜的,还有段文字描述,不知道丝瓜里实际着弹点准不准 The optic is zeroed on the 400m concept, meaning that if you shoot from 100m your point of impact should be about 22-25cm higher than your point of aim. The large chevron is used from 0-400m (see the '4' on the right of the vertical hash marks). Difficult to see in the photo but there is a tiny dot almost part of the large chevron, which is used for 500m targets. The second and 3rd chevrons are used at 600m and 700m respectively.