The Both ends of the test leads are pure copper alligator clips. The maximum width of the crocodile clips opening is 10mm. Lead length: 3.3ft. Voltage: 1500V. Current: 20A, wire with nice silicone insulation cover and the alligator clips made of copper. The clips make it easier to grasp the item you are trying to read, allows hands-free testing, great for remote spaces.Perfect for all DIY electrical testing, electronic applications like automotive accessories and testing circuits on your vintage cars, trucks and motorcycle, classroom experiment, troubleshooting in the electrical industry, laboratory, home, These wire are good for up to 20 amps maximum.These are good sturdy leads with thick wire and nice clips. The clips had insulators to reduce the possibility of accidental shorting. Good quality leads that work great for moderate to low current testing.This really is a great set of Jumper or Tester wires. 14AWG High quality thick cables. Excellent leads that can be used to do a variety of electronic testing. It will works as intended in conducting electricity!Package include: 5PCS alligator clips test leads. 5 colors make it easy to distinguish them during use. Alligator Clips Electrical Test Leads/Jumper wires Material: Copper and Soft Silicone Jaw Openingd:10mm Nominal Voltage: 600V Testing Voltage:2000V Thick Cable: 14 Gauge Silicone Cable Diameter:3.5mm Length: 3 Feet / 39" / 1 Meter Current: 20 A Color: Red, Black, Yellow, Green, Blue 5 colors make it easy to distinguish them during use.