LaCroix Optical part #17598. Cemented doublet negative achromat, 46.975mm (1.849") diameter by -706.52mm focal length. Glass is S-BAH10 (dense barium crown with an index of 1.670) and E-F2. Has Broadband coating with less than 0.5% reflection in the 450nm to 650nm range. Center thickness is 20mm. Complete spec sheets for each element and combined will be included with your order. Unused. Only have a few.
