Installed this in our sliding window so the cats can come and go without me playing doorman all day. The adjustable width fit our window snugly and the full lock mode keeps them in at night when I need to. My two cats figured out the flap within a day.
Christopher★★★★☆
The 4-way lock is the main reason I picked this up, and switching between in-only and full lock is quick and firm. Fit my window without much fiddling, though the frame feels a little plasticky for the price.
Adam★★★★☆
The 4-way lock has been great for training, I keep it on in-only at night so she can't wander out. The window fit was a little fiddly to line up at first, but once tightened it hasn't budged.