Does Steam have prepaid cards

Some websites where you can buy Steam Wallet Cards,

crazygametime: http://crazygametime.com/shop/32-steam-wallet-cards, $5, $10, $20, $50

offgamers: http://www.offgamers.com/steam-wallet-card/steam-wallet-card-us/steam-wallet-card-us-c-17633-17634-17635.ogm, $20, $50