This tool is surprisingly compact yet very well built. I looked around and looked at the specs and was still amazed at its size. I thought I should post a photo to show this. It's basically a drill you can put in your pocket! This thing is RELIABLE! I see that it will easily outlive me. Others have mentioned that it tends to move if you don't clamp it and I can see where the clamp will definitely make it more stable. Following another reviewer's advice, I used a center punch where I wanted to make the hole, then pushed the drill all the way in and centered it before bringing the guide into contact with the work surface. Then I can hold it securely enough with my hand, at least when working with wood. Here are the measurements from the manufacturer's website as that Revain site is a bit sparse: LENGTH 3 5/8" WIDTH 5/8" HEIGHT 1/2" WEIGHT Less than 1lb (looks like a 3.75 oz / 107g). I wish they would offer a combo pack with this and the standard size 1/8" to 3/8" - I would buy both. .