These are bullet style wire connectors which could be used to make electrical connections between motors speed controls and batteries. FEATURES: - Solderless crimp style connectors with clear plastic insulators YOU WILL RECEIVE: - Ten (10) male connector terminals with insulating covers - Ten (10) female connector terminals with insulating covers REQUIREMENTS: - Wire strippers - Needle nose pliers or crimpers SPECIFICATIONS: - Terminal diameter: 4mm description revised by: SN December 30 2020.