Ob daim ntawv thov Patent tshiab tau txais

Tau tsim kho tshiab, tau ua tiav, chav tsev tau thov rau ob daim ntawv patent tshiab tau txais, uas yog qhov zoo siab, ob daim ntawv pov thawj yog cov khoom siv cable nuv hanger thiab cov duab kos duab tshiab.