What's "OBM" ?

Original box and manual. No need to be embarrassed, it's not exactly obvious.

Thanks much Sfar..... For the record, that seems kinda redundant too...since you indicate such in another part of the ad... and I would hope with high-priced/fragile gear this (inclusion of original box and manual) is the exception rather than the rule.

Oh well, at least I know now...

It's not always the rule. Some people think they have bought the thing they will keep for life and throw out the boxes. Also make sure they have the original foam oinserts with the box, since these are very engineered to protect the particular piece of equipment. Stuffing the box full of foam or peanuts is not the same