4 Way Locking:
No in & No out( Fully locked)
Free in & Out( Fully open)

Size
S:19.7*19*2cm
M:19.7*19*5.3cm
L:25*23.5*5.3cm
XL: 29*26*6cm

Note: Size S is a little different from other sizes. It's "thinner".

Function Instruction of the Switches:
Turn Red and Green switches to both sides, pet is prevented from entering or exiting house.
Turn Red and Green swithes to right side, pet is allowed to enter house, but prevent from exiting house.
Turn Red and Green switches to left side, pet is allowed to exit house but prevent from entering house.
Turn Red and Green switches to middle, pet can leave and exit any time.

Outer door frame size
Small: 20*19*2cm
Middle: 20*19*5.5cm
Large: 25*23.5*5.5cm
Oversized:  29*26*6cm

Inner door frame size
Small: 16*15.7cm
Middle: 16*15.7cm
Large: 19*18cm
Oversized:  25*22cm