The R-Series subwoofers are compatible with optional grilles, to provide added protection to the cone. The 12-inch models are compatible with the KTE-12G Grille System, while the 10-inch models are compatible with the KTE-10G Grille System (all grilles are sold separately).
There are four models of R-Series subwoofers: the R-W12D4 12-inch Dual 4 Ohm, R-W12D2 12-inch Dual 2 Ohm, R-W10D4 10-Inch Dual 4 Ohm, and R-W10D2 10-Inch Dual 2 Ohm.