In Cu 380A, 380 represents
The numbers included in the names of the devices refer to the surface area (in sq.mm) of the copper on the device. Metallic copper has a strong anti-feility effect.Park 23e pg: 496
Number of turns of copper wire
Surface area of CuT in sq.mm
Surface area of Cu in sq.mm
Effective life of CuT in quaers
Demography and family planning