Fluidmaster PRO75B PRO Side Entry Fill Valve with 1/2-Inch Heavy Duty Brass Shank Fluid master PRO75B PRO Side Entry Fill Valve with 1/2 Heavy Duty Brass Shank. Preferred by professional plumbers. 1/2 Heavy Duty Brass UK shank. For use in a toilet cistern or storage tank. Ultra Quiet. Minimal water hammer. Long life performance. Fast refill. Unique snap release for easy access and maintenance. Anti-siphon design prevents contamination of water supply. For use in a toilet cistern or storage tank 1/2 Heavy Duty Brass UK shank Ultra Quiet - Minimal water hammer Fast refill Anti-siphon design prevents contamination of water supply.