Heat treated alloy steel, Precision machined and sandblasted bits * Fits star fasteners with tamper resistant centers * Sizes: T-5 T-6 T-7 T-8 T-9 T-10 T-15 * Includes 1/4" hex to 1/4" square drive adapter to fit a cordless drill, nut driver, or ratchet. * Includes plastic storage case so the bits you need are always handy