A cousin of mine showed me a nice lil' gimmick he recently acquired off Ebay - unfortunately it was 2nd hand and only came with basic instructions - not even the name of the gimmick was included

The Magician displays a cylindrical brass tube aprrox 4 inches in length with a screw-on cap which is handed out for examination. Next a black bag is produced and the magician empties the contents onto the table - 5 brass rods all of similar length but all having different markings to distinguish them apart:
rod 1 has 1 red band around it
rod 2 has 2 black bands around it
rod 3 has 3 blue bands around it
rod 4 has 4 green bands around it
rod 5 has 5 yellow bands around it
(The colours are prolly wrong - it's just an example)
The magician turns his back (no peeking whatsover) and the spectator freely places 1 rod into the tube, screws the lid on and hides the remaining 4 rods out of site.
Now I don't want to say too much about the next bit in case I give clues to the workings of the trick, but when the Magician turns back around he can accurately predict which rod is in the tube (he can even tell if someone is messing around and not placed a rod in at all!)
Everything is completely examinable from start to finish and no sleights of hand are necessary (just my kinda trick lol!)
My question to all you helpful ppl out there (grovel grovel) is - what's this trick/gimmick called and where the devil do I get hold of it plzz ?
I've been scouring various magic shops etc on the internet but to no avail.
Help plzz - I've even tried offering my cousin more money than what he paid for it - but he won't part with it

