I have a large die grinder with a 1" mandrel so I had to drill out the center flanges. At the time, the wheel was too wide for my grinder, so I made a 1/2" steel spacer. The tube is bent to fit the end cap. After adding five longer bolts, I was able to use the grinder with the new brush let it run. This is an amazing spoked wheel considering its size, weight and low price. As my title suggests, this is the best price I have ever received on a mail order item. Just wow.