Credit card company Visa has announced the availability of its Visa Micro Tag, a key-fob payment device embedded with the firm's Visa payWave contactless technology.

The Micro Tag is designed to attach to a key ring, and allows cardholders to pay by simply waving the fob in front of a smartcard reader without the need physically to swipe or insert the device into a point-of-sale terminal.

The technology allows financial institutions to offer cardholders a companion smartcard device to an existing Visa credit, debit or prepaid account.

"Visa cardholders consistently say they would like to use their Visa accounts at more merchant locations and are looking for faster and more convenient transactions," said Pam Zuercher, vice president of product innovation and coordination at Visa USA.

Visa Micro Tags can be easily made and personalised as part of an automated manufacturing process similar to that of standard cards.

The tag can also be made into a variety of shapes and sizes, from flat to three-dimensional, offering a number of design options.

Visa's payWave contactless technology was introduced in 2005 and has achieved rapid popularity.

Customers in the US enjoy the convenience of not having to sign for payments under $25 at convenience stores, sporting venues, petrol stations and fast food restaurants.