MS-400-3177-PL,  Fits most Infinity microscopes with smaller RMS sized threads.
 
Specifications
20x Plan Achromat objective
N.A. 0.50
Working distance 1.56mm
Provides a flat field of view
Infinity corrected
Corrected for No. 1 ½ coverglass
RMS threads
Shipping size 9x7x5 inches
Shipping weight 1lb