Hi, again I have this idea. Theres lots of ''credit card power banks'' in the market, but the good ones (3000mah-4000mah) are about 7mm-8mm thick, so they don't just slip in to your wallet. What do you think about if I start to sell CARD SIZED POWER BANK + CARD HOLDER WALLETS as a combo? Would you buy? Ideas? Happy Holidays!