Network cable testing kit, which is a set of tools used by technicians and network administrators to install, maintain, and troubleshoot network connections.
The kit typically includes tools for testing network cables (RJ45 and RJ11), crimping connectors, and stripping wire.
Network cable testers check for continuity, shorts, and other wiring faults.
Some testers have features like LED displays, port flashing, and the ability to measure cable length.
This specific kit appears to be a "13 Pcs Tool Set" from the brand YATO, though similar kits are available from other brands like Rubicon.
These kits are available from various online retailers and electronics stores.