For 29" Wheel w/ disc brakes Tubular aluminum rack is disc brake compatible. Fast, easy mounting of BabySeat(TM) II without use of tools. QuickTrackA(R) system compatible with all Topeak MTX TrunkBags and rear baskets. Material 6061 T-6 hollow aluminum Bag Compatibility MTX QuickTrackA(R) system Added Features Solid fender top, RedLiteA(R) Mount, Tail Light Mount Size 42.5 x 34 x 23 cm / 16.7" x 13.4" x 9" Weight 668 g / 1.47 lb Max Weight Capacity 27 kg / 60 lb, Meets EN 14872 / ISO 11243 Attachment Braze-on type