Cultiwool 6" x 6" x 6" Blocks of Cultilene Rockwool with Optidrain and Donut Rings - Case of 48Description Cultiwool 6" x 6" x 6" Block w Optidrain & Donut Ring (48 Blocks Case) by Cultilene: Cultiwool's growing blocks offer unique efficiency tied to product consistency. Key features include quick and easy uptake of water and the even distribution of water throughout the substrate, which make this growing medium outstanding. Superior Stone Wool Quality: Not only can consumers expect the top quality stone wool on the market, but Cultiwool also