In the eternal quest for space savings, the OD172SAPL Series stackable, aluminum dc fans feature two flat sides that allow for stacking them side-by-side with no wasted space. The components measure 172 mm x 150 mm x 38 mm and employ a die-cast aluminum frame and a PBT, UL94V-0 plastic impeller. The fans feature a dual ball bearing system and a polarity-protected, auto-restart brushless dc motor. They are also available with a tachometer (5V/TTL) output, locked rotor alarm, and with thermistor, PWM, and constant-speed controls. Available in 12, 24 and 48 Vdc versions, the OD172SAPL fans offer voltage ranges from 8 to 14 Vdc, 15 to 28 Vdc, and 28 to 63 Vdc, respectively. Airflow ranges from 120 to 225 CFM, with speeds from 2,000 to 4,000 rpm. Additionally, operating temperature ranges from -20°C to +80°C and life expectancy is up to 60,000 hours. Depending on the model, price ranges from $72 to $74 each in OEM quantities. ORION FANS, Dallas, TX. (800) 323-2439.