... length:4mm; 3)aperture:1/1.8; 4)mount:M12*0.5; 1)name:day and night board lens;2)focal length ... :4mm;3)aperture:1/1.8;4)mount:M12*0.5 ... are 2.1,2.5,2.8,3.6,25,4,6,8,12,16 (mm) etc or as your requirement ... .The aperture of lens are 1/1.2,1/1.4,1/1.6,1/1.7,1/1.8,1 ... then I will make a best PI for you,thanks! day and night board lens