Don't know, but they don't look like bargains or undiscovered gems to me. If they are like the UO MK-70s in correction, that would be okay at f/6 but perhaps not very satisfying at f/5. Twice I've tried the 40mm UO MK-70 and just wasn't happy with it in my 10" f/5, although my dissatisfaction with seagulls at the edge of field was rivaled by my frustration with the very thin, undersized barrel with the safety undercut in just the wrong spot for me to parfocalize the eyepiece (ended up wobbly in the focuser).
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Mike
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Mike
