The Magnum handheld receiver is multi frequency, frequencies are 216-221, takes 4 AA batteries. The short antenna is non-directional, magnetic mount, the multi arm antenna will have a frequency etched on the handle or near it, probably 216 or 217, i used it on 217. The blue box, I think is a Wildlife Materials, should say on it, but it was a 217 frequency only, not multi and it needs a new charger, but it did come on, just hard to see the menu and numbers. it can be sent  to Wildlife, they will completely

restore it for a fee, it worked and came on when it was charged.

Its all being sold "as is" with no warranty and no returns accepted. Thanks.