For MTB or heavy commuting use. Improved QR mechanism is more secure and easier to use. Compatible with all MTX Trunk Bags, 20 lbs. carrying capacity. Includes two rubber bungees and safety reflector.Clamp : QR fits ø25.4~ø31.8mm (shims Incl.)Material : Aluminum Beam.Bag Compatibility : MTX QuickTrack™ System.Max. Weight Capacity  : 9 kgs / 20 lbs.Added Features : Rubber Bungee,Safety Reflector,RedLite Mount,Tail Light Mount.Size (L x W x H) : 54 x 12.7 x 8.1 cm,21.3” x 5” x 3.2”.Weight  :680 g / 1.50 lbs.(A-Type) - For XS and S size frames(E-Type) - For S and M size frames(V-Type) - For M and L size frames