The PC-668R is a ceiling-mount speaker with an integrated resin panel and speaker frame. It features a spring clamp mechanism for easy speaker mounting to the ceiling. The slim speaker frame design allows it to blend into the interior design of the application easily. The input impedance can be easily adjusted by changing the tap of the transformer. Toa PC-668R specification: RATED INPUT 15 W (100 V, 70 V line) IMPEDANCE OPTION 100 V line: 670 Ω (15 W), 1 kΩ (10 W), 2 kΩ (5 W), 3.3kΩ (3 W)70 V line: 330 Ω (15 W), 670 Ω (7.5 W), 1 kΩ (5 W), 2 kΩ (2.5 W), 3.3 kΩ (1.5 W) SENSITIVITY 96 dB (Pink Noise 500 Hz – 5,000 Hz / 1W, 1m) FREQUENCY RESPONSE 65 Hz – 20,000 Hz (at 20 dB below peak SPL) SPEAKER COMPONENT 20 cm (8″) double cone-type DIMENSIONS FOR FIXING HOLE Mounting hole: Φ250±5 mm (Φ9.84″±0.2″)Ceiling thickness: 5 – 25 mm (0.20″ – 1.98″) SPEAKER MOUNTING METHOD Spring clamp FINISH Panel: Polypropylene resin, traffic white (RAL 9016 equivalent)Grille: Surface-treated steel plate net, traffic white (RAL 9016 equivalent), paint DIMENSIONS Φ280 × 90 (D) mm (11.02″ × 3.54″) WEIGHT 0.96 kg (2.12 lb) ACCESSORY Paper pattern …1