5 pcs package 40mm x 10mm fan ball bearing for 12V 3D printer replacement fan or 5V Raspberry Pi 6400 RPM @12V,6.71CFM, 2 Ball Bearing 1500 RPM @ 5V Dimensions:40X40X10mm, wire Length:300mm,28.6db(A) - bare wire Low speed at 5V for Raspberry pi Regular Speed at 12 V for 3D printer or Mini ITX projects