I am looking for a "personal item" bag with the following:
No larger than 40 x 30 x 15 cm (15.7 x 11.8 x 5.9 inches)
Shoulder/Messenger style
One large compartment vs lots of pockets
Trolley strap to attach the bag to my wheelie handles
No need to mention Rick Steves or Tom Bihn products as I am aware of them.