Promise Technology has unveiled the Pegasus J2, a mobile phonesized drive it describes as “the world’s fastest ultraportable Thunderbolt storage device”.

Promise said it is capable of delivering up to 750Mbps of throughput and is “the perfect complement for MacBook Air and MacBook Pro users”.

Available in 256GB and 512GB capacities, the Pegasus J2 will be available “early Q3”.

Promise Technology chief marketing officer Alice Chang said: “The Pegasus J2 brings unprecedented performance, fl exibility and portability.”