EFD20 ferrite core bobbin for LED transformer. Double grooves EFD20 horizontal bobbin 4+4 pin. Row distance=17.5mm. Pin pitch=5.0mm. Bobbin Size=20.0mmX20.0mmX10.3mm. EFD20 power transformers widely used in electrical equipments, medical equipments, communication equipments, power supplies, vehicle electronic equipments.