Prime Exposure Hill Assist Retarder 20LPrime Hill Assist Retarder has been purposely formulated to expose the aggregate on steep inclines and declines. Prime Hill Assist Retarder is the equivalent to Prime Retarder but has been formulated with a thicker viscosity to avoid runoffs down gradients and vertical surfaces. Prime Hill Assist Retarder works by delaying the set of the surface cement exposing the aggregate in the concrete. The easy to see fluorescent green colour ensures even