Slow Willie is a dry, powdered concrete retarder product conveniently packaged in easy-to-use one pound bags. It's easily mixed in with concrete during the placing operation giving you greater control. This must-have power concrete retarder saves you money and time. Delaying the setting time allows the operator time to reach proper clean-out locations. This pre-packaged retarder works well with any mix and will not affect structural concrete strength. Use one bag to delay one yard of concrete for up to 3 hours. (20ea. 16oz. bags per box/pail). Sold in either a box or pail.