1、These bullet crimp terminals are made of tin plated brass for better electric conductivity. 2、The insulator material is rubber of high insulation capacity. 3、These terminals and insulators are both flame retardant,more safe. 4、These tools are especially suitable for connecting electric wires. 5、These terminals can work at high frequency,more convenient. Features: These bullet crimp terminals are made of tin plated brass for better electric conductivity. The insulator material is rubber of high insulation capacity. These terminals and insulators are both flame retardant,more safe. These tools are especially suitable for connecting electric wires. These terminals can work at high frequency,more convenient. Specification: Working Frequency:High Frequency Character:Flame Retardant Connector Material:Tin Plated Brass Insulator Material:Rubber Package List: 20 x 4mm Female Golden Dual Hole Connector 20 x 7.8mm Transparent Insulating Sleeve 40 x 3.9mm Male Golden Bullet Type Terminal 40 x 3.9mm Transparent Male Terminal Insulating Sleeve