These are simple risers for the Hobby Lobby Play Train Table ( https://www.hobbylobby.com/crafts-hobbies/hobbies-collecting/train-sets/play-table-train-set/p/80957978 ).  These risers slip on the legs and bring the table up 2 inches.  Our grandson loves his table and is starting to outgrow it but by using these risers we expect to get more time out of it.  I printed them with 15% gyroid infill in PETG but I think one could get away with 8% gyroid.  

I designed these so they would be streamlined and not have an 'elephant' foot or similar to stub toes on!