Introducing Grassman's 'SprinkBak Pro' sports field system. br Incorporating the Patented D.U.C.C shock and drainage underlay from Grassman. Tested by Sydney University and approved for field use by Hockey NSW, FIH, AFL and more. br br Grassman is Australia's leading synthetic turf manufacturer and specialists in producing the highest quality artificial surfaces for sporting and leisure applications. We are Australia’s first synthetic turf manufacturer and successfully maintained its position as an industry leader for over 30 years. Grassman, Unit 8.