Leitz λ First Order Red Compensator for Polarizing Microscope.

Carl Zeiss Jena Microscope λ/4 (Lambda 4) compensator slider for pol microscopes

Leitz Microscope -Polarizing / Centerable - 5 Place Centering Nosepiece

LEITZ/LEICA Polarized microscope adjustable compensator 0-315 ORTHOLUX II POL BK

Leitz Microscope Accessories Polarization compensator Adjustable plug-in board

25mm - Microscope Full Lambda Wave Plate - See Specs