The higher draw weights and ever increasing arrow speeds of compound bows require sights built to withstand the extra shock and vibrations. As a result, compound target sights are generally heavier than their recurve target sight cousins, with bigger threads and chunkier components. There also Compact sights, usually fitted with 3 or 5 fibre optic pins. Although these sights are adjustable, they are not designed to be constantly adjusted like the compound target sights. Rather, each pin is adjusted to a fixed distance (typically 20, 30, 40, 50 metres) and everything in-between is for the archer to judge.