The bag is a T-Bag Saddle Roll. T-Bags are very well-made..unfortunately they don't make them anymore (they were bought by someone else..there's a thread on one of the HD forums), but you might be able to find one out there...
Youtube video:
It's a 'hard' bag in that it keeps its shape when empty...sort of like stiff cardboard covered with ballistic nylon. Some call it as a 'hard top' bag because the flap that opens up is 'hard' though covered in the same ballistic nylon as the rest of the bag. The ends of the bag are a zippered separate storage compartment (albeit small)..there are similar bags with the T-bag logo that do not have the zippered pouches at the ends of the bag. The dimensions of the bag are 16" (length) by 9 " (diameter). Since T-bags are no longer available for the most part (though there are still some still out there), I've started using Wolfman luggage.
Hope that helps!