This legendary barlow is as good as it gets. Remains invisible in the optical chain so you can use it for that high power observing with confidence.
I have two of these I was going to use for binoviewing, but didn't really enjoy using them that way. I remember using this barlow once to try it in the bino, and that's about it. Optically and mechanically this barlow is in like new condition, with original caps and packaging. Complete with non-marring Clicklock holder.