... lens; 2)focal 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 ... )etc.As to the fixed focal.There are 2.1,2.5,2.8,3.6,25,4,6,8,12 ... your requirement.The aperture of lens are 1/1.2,1/1.4,1/1.6,1/1.7 ... ,1/1.8,1/2.0 and so on ...M.O.D of lens ... are 0.2,0.3,0.1,0.15(m)The mount ...