Black Leaf' 'BL' Al. Weed Grinder, silver, 4pc. Ø 90mm This professional super-size CNC machined, Aluminium Weed Grinder with plenty of capacity to store your ground herbs, in the middle section. On the top lid, the 'BL' (' Black Leaf ') logo is printed and rotates on a nylon friction ring, to avoid inhaling metal particles. The lid is held fast by a magnet when not in use.