The Topeak MTX Trunk Bag DXP with Panniers uses a unique material process to provide Topeak's largest, stiffest, and most weather resistant MTX series bag. In addition to the expandable top section and rear water bottle holder, the side panels expand to full panniers maximizing capacity. Compatible with all MTX QuickTrack® racks with attachable side frames. MTX Dual Side Frames are required when using panniers on MTX BeamRacks.Topeak MTX Trunk Bag DXP with Panniers FeaturesAdded Features: Water bottle holder, Shoulder strap, Carrying handle, 3M™ reflective strip, Safety light clip, Elastic top bungees, Optional rain cover (3M™ is a registered trademark of 3M Company).Bag Attachment: MTX QuickTrack® with attached side panelsCapacity: 22 ... More info