Makes filling resin and mineral tanks much cleaner and easier10" opening narrows to 2.5"Can be used to refill 2.5" and 4.5" filter cartridge filters as wellDurable plastic constructionThe styrene funnel sits into a tank opening for stability when pouring media.Product FeaturesMulti-Use FunnelThe funnel can be used to refill mineral & resin tanks, 2.5-inch & 4.5-inch filter cartridges, plus many other things