... connectors 1.Material:golden or nickel plated 2.Size: 4.0mm, female and male 3.High quality and good price ... . The sizes include: 2.0mm, 3.0mm, 3.5mm, 4.0mm, 5.0, 5.5mm, 6.0mm, and 8.0mm ... It is mainly used in motor, battery, electro-hydraulic governor.4. It is convenient used in socket. So it is prior ... is prior to use in High-power electrical, such as audio, receiver, enlarger.PS:It is very kind of you ...