The solid pressed steel D ring cannot come open and the wide flat strap is folded through it
This hanger style has been popular with framers and their customers for many years. Picture can be hung on most hooks or screws in the wall.
This hanger is 84mm long. Holes are 4mm dia, use 3.5mm or 4mm dia pan head screws.
Load Testing: This hanger was tested and shown to have a Safe Working Load of 17kg. Which indicates that the screws would probably pull out of the wood before the hanger failed.