These tactile switches for the Game Boy Advance SP are great for modders on a budget who are looking to improve the feeling of their GBA SP's L and R triggers.
Higher-quality clicky tactile switches are also available.
Essentially the exact same as the original Nintendo piece that needed replacing, no complaints about the performance. You buy a button, you get a button.
Had to bend the contacts into shape to put in the through-holes, though.