PAIR OF E-10 V.3 D4 - Sundown Audio 10" 500W RMS Dual 4-Ohm EV.3 Series Subwoofers RMS Power = 500-watts | Xmax = 14mm one-way by 70% BL | Vented magnetic gap Vented pole piece with optimized geometry | Black Aluminum 2.5 voice coil former for superior heat dissipation | High Temperature 4-Layer copper voice coil wire Spring Loaded Terminals | Stitched-On Mini-XL Tinsel Leads to prevent fatigue and failure Box Recommendations: Sealed: 0.5 cu ft | Ported: 1.0 cu ft | Displacement: 0.11 ft^3 | Cutout Diameter: 8-7/8" | Outside Diameter: 10" | Depth: 5 5/8" | Recommended Tuning: 32hz | Recommended Port Area: 16 in^2