If you're like and like nice things, but also have cats, this may be for you. I have a standard Ikea Besta TV unit with bookshelf speakers placed at the front corners. Guess what animal likes to jump on speakers just for fun? TL;DR: my cats dropped my speaker several times, ruining the finish and destroying the grille. These endstops are designed to be VHB-taped onto the sides of a Besta countertop and secure your bookshelf speakers so (hopefully) they don't get bumped off onto the floor. I've used a simpler version of these for a while and so far, no cat has managed to drop my speakers again.

I use my speakers on small felt spacers, so the 30mm height of these stoppers is sufficient. This may not work for you if you have spikes or another sort of stand. I just wanted to keep everything simple. Printed solid in ASA and with infill in PLA. Either works. Front pieces are left and right-specific. Rear pieces are interchangeable.