High-quality silent fan, 80 x 80 x 25 mm, 12 V, 4-pin PWM, max. 2200 rpm, max. 17.7 dB(A), >150,000 h MTTF The famous 80 x 25 mm models of the A series benefit from the Flow Acceleration Channels and the AAO (Advanced Acoustic Optimisation) chassis for superior cooling and silent performance 8cm format ideal for compact PC cases (HTPC, ITX, Small Form Factor) and other racks (suction or extraction), replacement fans for NAS and other devices, etc. 4-pin PWM version for automatic speed control via 4-pin PWM connectors, extended speed range of 400-2200 rpm, stops at 0% PWM for semi-passive system Chromax.black.swap version characterized by a completely black look, fully customisable thanks to the removable anti-vibration silentblocks red, black, white, blue, yellow and green (4 of each colour)