Very small, as you would expect. Install took some slight improvisation, as the original triggers are secured to the PCB's metal bracket via 4 plastic nubs on the underside, which these lack. Besides de-soldering, I had to melt away these tiny bits to fully remove the old triggers. It only took a few seconds, so no big deal. Another unclear aspect of these replacements was how they have 4 metal prongs, though you only need to solder on 2. Before soldering these on, I folded 1 pair of prongs under the trigger, around a credit card to reduce the likelihood of them breaking. This also conveniently made them act as hooks, holding the button on the bracket, and kept the new triggers the correct distance from the PCB to allow proper functioning. Once soldered on, they worked (and still do so far) perfectly. The feel is comparable to the A/B buttons on a GBA SP. These make an audible click when pressed. Highly recommended product for anyone who prefers highly responsive trigger buttons!