It sounds like you’re referring to a JSB Cable Extension 4-way 3m, which likely refers to an extension cable with a 4-way socket and a 3-meter length. These types of extension cables are commonly used for distributing power to multiple devices from a single power source.

• JSB might be the brand or manufacturer.
• 4-way indicates that there are four outlets or sockets where you can plug in devices.
• 3m indicates the cable’s length, which is 3meters.

This type of cable would be useful for connecting several devices that are not close to each other, or when you need to extend the reach of a power outlet.