<prompt> In CuT 200, the number stands for:SurfaceAreaofCopperWeight of Cu in microgramWeight of Cu in milligramEffective half life in weeks  <response>: Ans: A Surface... The number included in the names of the devices refer to the surface area in sq, mm of the copper on the device. Park 21st459 IUDs: Review of Facts CuT-200 B being used in India , under the national family welfare programme,Later CuT 380A is introduced in the programme. Studies have shown that the effectiveness of copper device is directly related to the amountofcopper surface area usually this is 200 or 220 mm2- Park 19th395 IUD is not a method of first choice for nulliparous women. They have more problems such as expulsion, low abdominal pain Si pelvic infection.intra-Uterine Devices; Classification 1st Generation IUDs inert or non medicated devices 2nd Generation IUDsEarlier devices Copper 7 Copper T - 200Newer devices Variants of the T devicei T Cu - 220 Cjj T Cu - 380 A or Ag Nova TMulti load devicesi-Cu-250ii-Cu-375 3rd Generation IUDs Hormonal deinces Progestasert LNG-20 Mirena13 