<prompt> Why is it called Cu T 200200 sqmm of Cu over loop200 mm of Cu over loopFor 200 days, Cu concentration does not changes200 sqcm of Cu over loop  <response>: In Cu T 200, the number included in the name of the device refer to the surface area in sq.mm of the copper on the device Reference : Park;s textbook of preventive and social medicine,23rd edition, Page no: 496 