B+W NL 1
This lens is a +1 diopter with a focal length of 1000mm.

B+W NL 2
This is a +2 diopter lens of 500mm focal length.

B+W NL 3
This lens is a +3 diopter with a 333mm focal length.

B+W NL 4
A +4 diopter with a 250mm focal length.

B+W NL 5
This is a +5 diopter lens with a focal distance of 200mm.

B+W Macro Lens
This lens has a diopter of +10 and a 100mm focal length. As it fills the frame of the 35mm format, life size to somewhat larger than life size pictures are possible.