This case is an optional accessory for our BK-3 backpack series. It attaches to the top of the backpack and is ideal for storing filters, matte boxes, spare batteries, audio equipment and other camera accessories. Features - Secure attachment, easy to put on and take offn- Durable 1000 denier Cordura fabricn- Can be used on the BK-Extreme or alone on a beltn- Lightweightn- Modular design allowing for greater customisation