The Tolsen 16521 is a 21mm socket designed for reliable work with various fasteners. It is crafted from heat-treated 50BV30 chrome vanadium steel and finished with polished chrome, ensuring the tool remains durable and resistant to wear over time. This socket features a 1/2" square drive, making it compatible with standard ratchets, breaker bars, and torque wrenches. To make your work easier, the head profile is specifically improved to grip fasteners with deformed edges that might otherwise be difficult to remove. It also includes a ball retaining groove to keep the socket securely attached to your drive tool, while its construction adheres to DIN3124 and ISO2725-1 standards for consistent performance in mechanical tasks.