If you are a HiTechPet door owner, and you live in a part of the country where there are seasons, you have probably experienced the occasion where the door opens and get stuck at the top of its travel.

This simple spring / stop prevents the door from getting stuck at the top of the track. Simply install in the door in place of one of the rubber door stops.

Onshape:
https://cad.onshape.com/documents/77368def6bd4d54fc2dfd7ac/w/b5f55f2935f2e22304632ed1/e/e3ee84ac1d3c0b918b7bfe30