This bag closes by means of a zipper. The carrying options for this bag includes a dual shoulder straps.
From Amazon
Targus Geolite Advanced Business Backpack Designed for Travel and Professional Use fit up to 15.6-Inch Laptop, Ocean (TSB96201GL)
Comet
Targus TSB96101GL laptop case 39.6 cm (15.6") Backpack Black
This product is also available at 3 unverified merchants.