Ortlieb Messenger Bag Pro. Brand new, never used. Retails $195. Very large. 
- Roll Top
- Reflective patches on sides and bottom, reflective striping on shoulder straps
- Shoulder, waist, and sternum straps for ultimate carrying comfort
- Waterproof
- $100

Dimensions: 50 cm x 39 cm x 15.5 cm
39 L capacity

Selling because this bag is way too big for me.
Email with questions.

Check out the Ortlieb listing for specific details.
https://ortliebusa.com/product/messenger-bag-pro/