Comments about Pro Optic Pro-Optic 5mm Long Eye Relief Eyepiece, 1.25":

I have 8"(203mm diameter) Newtonian; theoretical max. magnification was 406, it was told. I have used Televue 3x Barlow to my existing 10mm Sirius Plossl eyepiece to make 300 mag, but the image was not usable quality, so I have tried this 5mm to make 200 mag. without barlow, instead. Because , as we know that the optical price for using barlow is giving up some brightness.
It turned out to be rather good one. It may not have the greatest optical quality in the world but it seems to have decent quality for the price.
Yes, I would recommend this to my friend and potential eyepiece user who might considering 5mm with or without barlow lens.
I said that it's slightly long(about 4") and heavy but it's understandable considering it has 7 elements, not just 3 elements that many eyepiece employ including plossl I have. It's not too long or heavy.
Besides, it seems to be rugged & well constructed, not so flimsy or wimpy.
Therefore, overall I think it's good eyepiece.
Isaac