Minecraft wiki entry for Quasi-connectivity, associated text: A quieter floating button (right schematic) can be created by using a dropper instead of a piston and using it to push an item into a hopper, which pushes it right back (unlike the dropper, the hopper isn't affected by redstone components two blocks above it), but briefly activates a comparator output. This version updates the dropper with a hopper clock, which is a little slower and thus slightly less responsive, but smaller than a torch-repeater clock.