Bar Refaeli's new swimwear ad is sure to set pulses racing – but for most it will be less about her 'Little Black Bikini' and more about what she's not wearing.

The catwalk beauty - who is currently dating Leonardo DiCaprio -  poses in a skimpy two-piece in a new campaign for U.S. surfwear firm, Hurley.

Israeli-born Bar, 23, said: "Anyone who knows me knows that I am obsessed with finding the perfect little black bikini, [and] always searching for a timeless, sexy suit with the best fit."

The limited-edition Hurley Little Black Bikini by Bar Refaeli is available online from May 1 for a snip at $120. Fabulous bikini body not included.

A portion of proceeds will be donated to Boarding for Breast Cancer, a youth-focused charity that aims to spread the halt of the disease thanks to early detection and an active lifestyle.

See more sexy celebrity ads below