This bag closes by means of a zipper. The carrying options for this bag includes a detachable shoulder strap.
From Amazon
Port Designs Belize Top Loading Lightweight Padded Case for 15.6-Inch Laptops, Black
Technoworld PLC
Port Designs BELIZE notebook case 39.6 cm (15.6') Sleeve case Grey 110200
OnBuy
Port Designs BELIZE 15.6" Sleeve case Grey