The bag is very gently used - I had it on for about a month and changed bikes and colors. there is one tiny black mark 1/4 inch long and as wide as a pencil lead on the part that sits against the top tube.

I don't know the model number - but the bag is 5" tall, 4" wide and 8" deep at it's longest point. There is a zipper that can be unzipped to make the bag larger via a gusset of about 2 inches.

The bag mounts to your seat rails by a clip mechanism, and then there is velcro for around the seatpost and again on the seat rails. It is a very easy mechanism.

The bag has two internal stretchy bands to secure items as well as one on the outside for whatever and one on the back for a blinky light as well as silver reflective material.

Hope that helps.