IKEA Rågrund Shelf Leveling Feet

Bathrooms often have a slight slope to the floor towards the drain, making it hard to get vertical shelves. Rågrund being a tall narrow shelf only makes things worse. The feet are the same outer dimensions but can be printed with 1-12 mm insert to compensate for uneven flooring. They also serve the additional benefit of protecting the legs from water. 

Design by user_334057720 on MakerWorld (license: CC0).