3--5cm: suitable to carry
14.5cm: for most home windows and doors
17--21cm: suitable for hanging in the company or warehouse
Eight hanging mirror hanging method:
Concave mirror: you can hang in the room (now the location of doors and windows) and outdoor
Convex mirror: You can only hang in the outdoor
 
type 1                                          type 2
 
type 3                                        type 4