Camera adaptor 1.5x T2-mount Adaptors compatible with Evident (Olympus) microscopes of the BX, CX series U-TV1.5XT2

This refers to the magnification factor of a single microscope lens. A lens with the number 40 is referred to as a scale of 1:40 or simply a factor of 40 times. If you multiply the lens factor by the eyepiece factor, you get the magnification.