Since I had the problem that all Shelly holders obscured the connections unfavorably or pointed in the wrong direction, I designed a simple holder that can be mounted on top-hat rails etc. The holder is designed for all Shellys in the Plus series (square design). The connections can be screwed on from both sides, so it doesn't matter which way the Shelly is installed. The holes are approx. 60mm apart and the holder is approx. 75x44x19mm in size. They are holes for M3 screws.