Chapin International 1941 Industrial Open Head General Duty Concrete Sprayer for Professional Concrete Applications, 4 gal 3.5-Gallon Tri-Poxy tank for durability and a 4-inch wide mouth opening for easy filling and cleaning Compatible for most professional concrete applications, suitable for homeowners too (check chemical manufacturers instructions) Brass pump, wand, nozzle and shut off with lock on feature Viton seals and gaskets designed to handle a variety of chemicals (check chemical manufacturers instructions) Unique Tri-Lock seal feature that locks the pump cap tight