Abus Ultra 410 Mini Keyed U-Locks Size:5.5" Shackle These backpacks are very robust

These backpacks are very robust yet incredibly light thanks to the use of the extremely tear and abrasion resistant material Nylon 420D Oxford

Soft-touch ergonomic grip top with EVA foam grip and grip extension

It's rated to UPF 50 for sun protection

Merrell Air Cushion for impact absorption and all-day comfort

Solid welded construction

Abus Ultra 410 Mini Keyed U-Locks Size:5.5" Shackle These backpacks are very robustDouble bolted shackle for extra protection against cutting and torsion attack Shackle, body and supporting elements made from special temper hardened steel for cut and torsion resistance Industry leading corrosion resistance to ensure long life Automatic keyhole cover protects against dirt and corrosion Universal bracket easily mounts to round frames 15 35mm diameter