Proto Single 3/8" Drive 4mm Metric Hex Bit Socket, 2-3/4" Long, Great Pick for Pros and DIYers, Solid Toolbox Upgrade, Tough Bit Socket for Garages, Shops, and DIY Projects

Proto Single 3/8" Drive 4mm Metric Hex Bit Socket
✔️ 1 hex bit socket, 3/8" (9.53 mm) drive, 4 mm (0.16") size

The Proto single hex bit socket combines a driver bit and socket in one piece so you can turn screws and bolts with a ratchet. You'll see it in brake jobs, interior trim work, and machine repair, and it's ready to work hard every day.

✅ Pack size: 1 hex bit socket
✅ Brand: Proto
✅ Drive size: 3/8" (9.53 mm)
✅ Size: 4 mm (0.16")
✅ Measurement system: metric
✅ Length: 2-3/4" (69.85 mm)
✅ Mfr part number: J4990R-4M

💡 What's the difference between Torx and E-Torx sockets?
Torx bits fit into a star-shaped recess, while E-Torx sockets fit over a star-shaped bolt head.

• Torx bits are for internal star screws on brakes, trim, and electronics
• E-Torx sockets grip external star bolts common on European cars
• Plenty of shops keep both since many vehicles use each type