Lithi-Tek 4500 - 1 Gallon Penetrating Concrete Sealer and Densifier An industrial-grade, water-based, lithium densifier for use as a stand-alone product or as a primer to strengthen and harden concrete Strengthens concrete up to 50%, Increases abrasion resistance Excellent penetration, no change in appearance, low VOCs Concentrated: makes up to 4 gallons