Fashion brand COS has released a limited-edition backpack to mark the opening of this year's Serpentine Gallery Pavilion.

The Serpentine Bag was created by the COS design team to celebrate its partnership with the gallery on the Park Nights programme – a series of live art, performance, theatre, film and poetry events taking place over the summer at the SelgasCano-designed structure in London's Kensington Gardens.

The backpack features a light-grey canvas sack and is carried with darker leather straps or a top handle.

"Functional and modern, the backpack is made from soft canvas with contrasting raw-edge leather straps and handle," said COS.

The top of the bag folds down and is secured with a buckle to cover the main internal pocket, while additional zip-up compartments are integrated into the back panel.

Following Renzo Piano's leather bag modelled on his new Whitney Museum in New York, this latest accessory designed for a building is available online and from selected COS stores in London. Proceeds from sales will be donated to the Serpentine Trust.

The Serpentine Gallery Pavilion is an annual commission given by the gallery to an architect that hasn't yet built a project in England.

The year's design by the Madrid-based studio – the 15th pavilion in the series – comprises a series of tunnels covered with colourful translucent plastic membranes and ribbons. Watch our video interview with the architects about the project.

COS has supported the Park Nights programme for three years. Last year, the brand designed two pairs of leather shoes to coincide with the launch.

Since it was founded in 2007 as part of the H&M group, COS has commissioned a number of designers and studios including Nendo and Snarkitecture to create installations at events such as Milan design week.

In March, the brand enlisted architect André Fu to create a presentation space for its latest collection on a Hong Kong pier.