That’s the catchy name for a smart little device created by Inventrade International. I don’t think anyone else makes them. Small, safe and highly functional, they cut paper along a folded edge, of any length. I’ve used them for years and passed some round my origami class, who were delighted and promptly asked me to buy some for them. If you buy in real bulk direct, the price is really cheap, but even sold on by the BOS they are only £1.50 (plus P&P).
The knack in using them is to not make the crease to firmly, so the internal knife blade can slide between the layers to do it’s thang. As they get older, they do become less than %100 functional, but I would recommend them to anyone. See a previous post on the subject.
Anyway, they arrived today (just too late for this weeks class) so my students can have their very own BOS branded envelopener!