: weed leaf grinder - New. Black Leaf - Aluminum Herb Grinder - 4-part - 40mm - Choice of 9 colors. This CNC machined, anodized metal 4-part weed grinder from Black Leaf has sharp, diamond-shaped teeth to gnash through your bud, a pollen screen, and a kief catcher to filter and collect pollen dust that can be gathered for re-use with the included scraper.