What's your go to gift for a new baby- preferably something with free shipping or on Amazon Prime?

We've got a few babies recently born or about to be born, who I need to send something (they sent something when C was born and I want to return the favor) but we aren't super close so it's not like I totally know their taste or needs. Trying to think of some easy things that every parent needs and it's ok if they get duplicates. Ideally in the $20-30 range.

They live far away so I'll just have it shipped right to them.