Usage Tips:Quick release: the car battery clamps are designed for users who usually replace batteries. Please take a look at the picture 4. The red and blue quick release connectors allow for quick disassembly to charge and store your ship or vehicle batteries.Professional design: the battery connection terminals are designed for top post batteries and side-post batteries with standard post adapters. Especially in tight spaces, the connectors are ideal for batteries.materials: battery terminals are made of copper coating with corrosion resistance, good electrical conductivity, easy wiring and strong connection. Plastic cover is an insulation cover that is dust and moisture resistant and has a long service life.Widely used for vehicles: the thread on the terminal makes installation easier. It is not only 12V battery terminals, but also 24V and 48V battery terminals used for battery extension, parallel connection and grounding connection for car, vehicle, caravan, etc. can be used.Easy to useYou will get both positive and negative battery terminal connectors. Please check pictures 4 and 5. If you want to replace the battery with a wrench, simply lift the battery pole covers (insulation tray) that can remove the battery and then attach a battery to the car battery terminals by clamping the cap.Specification: Material: plastic and copper. Colour: Red & Black Inner diameter (positive): 17 mm. Internal diameter (negative): 16.5 mm. Features: Battery quick release buckles red and blue allow you to quickly remove and store the battery of your boat or vehicle. Ideal for battery installations in confined spaces. These are only intended for round conventional terminal batteries. Attach the battery clamps by clamping them and lifting the caps to remove them from the battery terminals. Package includes: 2 pairs (left and right) battery terminals. Remarks: Please check the size chart carefully before making payment. Please allow for a difference of 0.5 - 1 inch due to manual measurement. (1 inch = 2.54 cm). The color of the actual items may vary slightly from the listing images due to different computer screen, thanks for your understanding.