These 12V 40x40x10mm Brushless Fans can be used to replace a broken hotend cooling fan for 3D printers; or can be used to cool the components inside the PC, such as the motherboard, RAM, VRMs, SAYA/M.2 SSDs, among others. The fans can also be used to cool down battery chargers, battery backup UPS, DVR/NVR systems, DIY projects, RAID enclosure, switches, X-Carve Controller, Stepper Motors, consoles (PS4, Xbox, etc.), humidifier and other small appliances.