A bird feeder with a slot for a transparent plastic to see the seed level. I used some blister pack for the window, just cut it to fit.

Fusion project: https://a360.co/32GYglQ

Plan to use it with safflower seeds for cardinals (UPD: cardinals and chickadees love this feeder.)

Looks like the lid is held there with friction only, so if a squirrel uses it as a spring board it may open. Hope it won't. Thought of hanging it with the screws, but then found some Gorilla mounting tape. Let's see how it survives the rest of the summer and the cinter.

UPD: relplaced the lid with a newer version, the one with an additional lip preventing it from tilting open.

UPD2: put another version of the lid, less likely to be opened by squirrels.