* No Power Supply included:To optimize performance of your Three Hundred, your choice of power supply is crucial. Antec strongly recommends choosing from our NeoPower or TruePower series.* 9 Drive Bays:• External 3 x 5.25\"• Internal 6 x 3.5\" for HDD* Cooling System:• 1 rear 120 x 25 mm TriCool™ Fan with 3-speed switch control.• 1 top special 140 x 25 mm TriCool™ Fan with 3-speed switch control• 2 front (optional) 120 mm fans to cool the hard drives• 1 side (Optional) 120 x 25 mm Fan to cool graphic cards* Washable air filters reduces dust build up in your system, which helps keep your system cooler* Perforated front bezel for maximum air intake* 7 expansion slots* Top mounted I/O ports for easy access• 2 x USB 2.0• HDA & AC’97 Audio In and Out* Unit dimensions:• 18\" (H) x 18.3\" (D) x 8.1\" (W)• 45.8 (H) x 46.5 (D) x 20.5 cm (W)* Weight:• Net: 15.9lbs / 7.2kg• Gross: 18.7lbs / 8.5kg