Upgrade factory vehicle audio with this Infinity Primus four-speaker bundle, featuring one pair of Primus 603F 6.5-inch 2-way speakers and one pair of PR503F 5.25-inch 2-way speakers. The mixed-size configuration is ideal for vehicles using larger front door or rear-deck speakers along with compact rear door, dash, or other factory locations. The Primus 603F speakers combine polypropylene woofers with edge-driven silk dome tweeters to deliver controlled bass, defined midrange, and smooth high-frequency detail. Rated at 50 watts RMS and 150 watts peak power handling, the 603F pair has a 55Hz-20kHz frequency response, 92dB sensitivity, and 3-ohm nominal impedance. Expanded woofer cone architecture provides increased radiating surface area for fuller output from a compact speaker design. The PR503F 5.25-inch pair brings the same Infinity Primus 2-way sound approach to smaller mounting positions. Its woofer and silk dome tweeter design helps reproduce detailed vocals, crisp instruments, and balanced music across a wide range of genres. Rigid vented basket frames help dissipate heat during demanding playback. The 603F pair includes mounting screws, speed clips, pigtail cables, foam gaskets, stickers, and an owner's manual. Verify vehicle mounting depth, cutout size, wiring connections, and any required installation adapters before fitting.