Yeah, they got it listed as a BA and a Radio Improved. Can't be both, so Radio Improved it is. I notice they don't give you the serial number and it's too hard to see in the picture. Buyer beware ...I think these late serial Radio Improved horns are sometimes described as the 'Dorsey Model series I' but yes they are really just a batch of Radio Improved horns with serial numbers and finished in the Balanced Action range. The 'Dorsey Model series II' was the one with the balanced action style key guards.
Coincidentally there is another one of these horns on ebay at the moment: