Big Bertha Magnet is a very powerful magnet made from a material called neodymium which is the most magnetisable material on earth. This magnet will only lose approximately 5% of it's strength over 100 years, with no batteries to change or charge; it is classed as a permanent magnet. Big Bertha Magnet should be used as a complementary therapy, to boost the therapeutic effects of conventional medicine and treatments. Big Bertha Magnet can reduce your pain instantly, but normally easing can be experienced within thirty seconds to one minute. Longer lasting results can be achieved by wearing magnetic wrist products, which can provide therapeutic effects 24/7. Please consult your GP if you have persistent pain to get a diagnosis of what is causing the pain. Please read the instructions for use and the health and safety information before using Big Bertha Magnet.  Please remember to drink plenty of fluids when you first start using any magnetic therapy products. DELIVERY UK - FREE P&P OUTSIDE OF UK - £5