Some of these technologies are VRC (vented reinforcement collar), Elevated Frame-Cooling and Floating Cone Attach Method. The low profile 8W1v2-8 works best in small enclosures making it ideally suited for smaller or hard to fit vehicles. The mounting ring is removable and customizable making installation of the speaker grille-mesh simple with no extra required hardware. (Grille mesh inserts are sold seperately.) This also allows the ring to be painted to match the desired look of the car interior. The optimum power range for the 8W1v2-8 is 60-125W, and running over 150W will void the manufacturers warranty. To run over 150W, you will need to use a larger model in the W1v2 series, or upgrade to one of JL's other subwoofer lines. The 8W1v2-8 has a free air resonance of 36.60 Hz with a nominal impedance of 8 ohms. However, like all the W1v2 sub-woofers, there is a 4 ohm version which is sold as the 8W1v2-4 allowing consumers to pick the subwoofer which suits their audio set-up.