This CHANCS aluminum handwheel is one of those simple but super useful workshop accessories. The 20mm diameter gives you good grip, and the knurled edge means your fingers won't slip when making adjustments. It's got a 4mm bore (about 15/32 inch) that's 15mm deep, perfect for various shafts and controls. The black anodized finish looks professional and resists corrosion. I've used these on everything from slide displacement platforms and stepper motors to milling machines and lathes. The CNC machining is precise, so it fits snugly without wobbling. The double set screw design keeps it securely locked in place once you position it. Great for when you need fine control over adjustments on instruments, machinery, or any equipment where you're manually setting positions. The aluminum construction makes it lightweight but still durable enough for regular use. At this price, it's worth keeping a few around the shop for various projects.