mobile phone signal jam mer ?

BRAND NEW IN BOX, MAINS CHARGER, CAR CHARGER, AERIALS AND BOOKLET. WORKS UP TO 30M ON MOST PHONES. WILL NOT DAMAGE IN ANY WAY, SIGNAL RETURNS AFTER SWITCHED OFF. GREAT PRANK FOR IN THE PUB ETC. TAKES A FEW MINUTES TO FIND AND BLOCK BUT WHEN IT FINDS IT ITS GONE. NO MORE NOISY MOBILE CHITCHAT ON THE BUS. BOUGHT THIS IN A BOX OF JOBLOT STUFF, 100% NEW AND 100% WORKING. CONTACT ME FOR PAYPAL PAYMENT, CAN POST FOR 5 EXTRA ANYWHERE 1ST CLASS RECORDED DELIVERY