The person who installed a couple of my rooms left this metal transition strip behind and I just have no clue how it's supposed to be used or where I can use it. It doesn't look like any of the usual T-shaped stuff I've seen everywhere else. After some research I've found it's "square shaped tap down transition" I think?? I see some illustrations of it being used between floating planks and carpet but I just don't understand how it holds things down on both sides. The one installation instruction video I've found has been very unhelpful. Can anyone explain to me how this is supposed to work and what I can use it for?