So this seems to be a pretty common question in threads about the Philips OneBlade "can it be used for shaving the body and/or more sensitive areas?"
This is Philips "official" response - get the OneBlade Body Kit, QP610/80 which includes a replacement blade, a "click-on skin guard for extra protection on sensitive areas" and a 3mm body comb.
I can't really say whether it's a good deal or not, certainly based against the cost of a single blade it's not really that great, but for those who're specifically looking for this application maybe it's the product you've been looking for. Amazon reviews seem pretty happy with it, YMMV. Free international shipping with Prime Day per previously posted deal.