Features all steel construction (not aluminum). Precision ground and hardened 1/2" tool bit capacity - standard for a #1 AXA holder Quick and easy height adjustment Special ZiN coated hardware for increased durability and strength Center bolt thread: M10 x 1.50 Quick change holders are incredibly versatile in the machine shop. Found almost exclusively on lathes, they allow you to quickly swap between tools with minimal setup time. AXA #1 holders will work with turning or facing tools and help to keep the job running smooth. The team at Colton Industrial Tools worked on giving their quick change holders a bit of an edge. They use a Zinc Nitride (ZiN) coating on all of the hardware to give it a more durable and rust resistant finish while allowing for smoother thread action. We think the coating looks pretty good, too. Colton Industrial Tools has a commitment to support their customers by offering a best in class 5 year warranty on all their products.  These holders are yet another example of Colton Industrial Tools living up to their motto of "Helping Makers Make Better.