The only downside I have for the Manta is those %$&@#*& ID o rings on the top cap. The top cap fit with both of the o rings in place was a little tight so when someone mentioned removing one of them I thought I would give it a try. The fit was great with one but I found that I sometimes moved the airslot off of alignment during use so I decided to put the second o ring back in.
At first i swore I had the wrong o ring. It seemed 7 sizes too big to go back in there. After spending a long time and a few choice words I did manage to get the thing back in place but there has got to be a trick that makes it easier.....unless that's the reason that no more will be made. Who can tolerate the labor cost to assemble that thing?
If you want to replace one of those o rings don't give up. It will go but plan to spend some major time doing the job.
Why did they choose ID rather than OD o rings? Sheeeesh.
Duane