I have the long version, Bintel branded. I noticed the current Bintel ones are short.
This explains why I get nearly 2.5x magnification in the 2" 2x barlow. It barlows to a 12mm effective FL. My eyepiece is lousy, as was confirmed by more experienced people at the Snake Valley camp last year.

Seagulls a long way in from the edge, and refocusing does not help. Much better in the barlow though.