The OD4020-24MB from Orion Fans is a 40 x 40 mm square tubeaxial DC brushless fan rated 24 VDC, 20 mm thick, with ball bearings, 8.0 CFM (0.224 m³/min) airflow and 2 wire leads.
The OD4020-24LS01A from Orion Fans is a 40 x 40 mm square tubeaxial DC brushless fan rated 24 VDC, 20 mm thick, with a sleeve bearing, 6.5 CFM (0.182 m³/min) airflow and 3 wire leads.
The OD4020-05LSS01A from Orion Fans is a 5 VDC square tubeaxial fan measuring 40 mm × 40 mm, with a sealed sleeve bearing, rated 6.5 CFM (0.182 m³/min), and 3 wire leads.