one-jpiece multifocal lens
单片焦透镜

• net micrometer eyepiece
• net radiance
• netting
• net unsaturated gain
• net weight
• network
• network diaphragm
• neural
• neuristor
• neutral
• neutral absorbent
• neutral atom
• neutralator
• neutral color
• neutral-density filter
• neutral density filters
• neutral gas laser
• neutralisation
• neutrality
• neutral line
• neutral mirrior
• neutral step filter
• neutral stepweaknener
• neutral step wedge
• neutral water glass