Materials RIP RAP Available Sizes* of RIP-RAPR-3 3” to 6”R-4 6” to 12”R-5 9” to 18”R-6 12” to 24”R-7 15” to 30”R-8 24” to 48”*Please note that up to 15% of the Rip-Rap can be above/below the specified minimum/maximum sizes