Flex Capacitor 25-40 - Bearing Blue

£105.00 Regular price £160.00
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The Flex Capacitor 25-40 is a beast of a backpack, constructed from durable nylon for rough conditions on the hills or in the backwoods and built with adjustability in mind - with versatility comes from innovation. When you loosen the expanding horizontal gussets, the 25L pack uncovers up to an additional 15L of cargo capacity for longer trips. Then cinch it back down for smaller loads or short hauls.

With ample quick-stash solutions on the straps, sides and bucket lid, ensuring there are plenty of places to store your mid-trail essentials. The Y-Flex suspension adds support, meaning this lightweight backpack can hit well above its weight class.

  • Materials: 100D Nylon-Poly Ripstop/420D Nylon Oxford
  • Hip Fit with S/M waist belt: 29" - 32" / 73.7 - 81.3 cm
  • Hip Fit with M/L waist belt: 32" - 35" / 81.3 - 88.9 cm
  • Capacity: 25-40L / 1525-2440 in3
  • Weight: 2 lbs 8 oz / 1.13 kg
  • Torso Fit: 16" - 19" / 40.6 - 48.3 cm
  • Dimensions:  23" x 11" x 8.5" / 58.4 x 28 x 21.6 cm


After first meeting in late 1963 at The Ski Hut in Berkeley, CA, Bob Swanson and George Marks teamed up and founded Sierra Designs in 1965 on the premise that all people deserve to have good gear for exploring the outdoors, regardless of their background or experience level. Sierra Designs pioneered many of the outdoor innovations taken for granted today - Cirrus Down filled sleeping bags, double sleeping bags and tent Swift Clips to name a few.

As lovers of all things outdoors, they recognise they must protect the places we explore and live - creating products that have as little impact as possible to the environment, transitioning to materials that use fewer resources, discard less and better protect people’s health.

Please Note: All stock available online is also available in our 178 Shoreditch High Street, London shop. Our friendly and experienced team can advise you, help with sizing and find you the perfect kit for your next trip. Come in store or contact us if you have any questions or need help.