- Barrel Jack Size (Diameter/Length)
- 5.5mm x 2.1mm: The most common size used for many consumer electronics, including CCTV cameras, routers, and small gadgets.
- 5.5mm x 2.5mm: Slightly larger than the 2.1mm and often used in higher-power devices like audio equipment.
- 4.0mm x 1.7mm: A smaller size typically used for more compact devices like some wireless routers or small portable electronics.
- 7.4mm x 5.0mm: A larger size often used for laptops and some larger equipment.