The TummyToys clasp is so simple: you just slide it through the piercing and snap it shut. TummyToys are specifically made for belly and body piercing. Beware of cheap imitations which are really just earrings with a heavier post...
.925 Sterling Silver Tummytoys Belly Sleeper Ring with small dangling jeweled cat charm, 14 ga
Silver Tummytoys belly sleeper ring with large teardrop crystal, 14 ga