Tumi Messenger/briefcase bag, model 26193D4.  It will easily accommodate a large screen (15.6") notebook computer, as my 14" Dell had ample room in the compartment.  The bag has many compartments, some quite deep.  Bag has been used as you can tell from the pics. 

The inside of the shoulder strap pad shows some wear see photo

The inside liner under the flap also shows some wear. 

Approximately 18 x 14"
Please ask all questions before bidding

Thank you for looking.

10/16 4