A 12 gauge Winchester/Western Compression formed Super-X shell for the handle, with a best badger bristle knot. Loft is 2" and handle is 2.125", for total height of 4 1/8". This is a small knot (18.5 mm actual dia.) and would barely fit in a 12 gauge. This brush actually works very well, and is weighted for good balance and heft, but it is a bit dainty for my tastes. I prefer 23 to 26 mm knots, but I'd need a 8 or 4 gauge empty shell for that, and those are difficult to come by. A 10 ga. would make a pretty good handle, but only about a millimeter and a half larger than a 12 gauge, and most modern 10 ga. hulls in plastic are made in such un-attractive colors. This is the photo of the brush immediately after manufacture, and before the brass was polished to high brightness. It looks better now. I made this a couple of years ago. .