LaCroix Optical part #17031 C. Cemented doublet negative achromat, 87.975mm (3.4636") diameter by huge -12025.97mm focal length. Has Broadband coating with less than 0.5% reflection in the 450nm to 700nm range. Center thickness is 21mm. Complete spec sheets for each element and combined will be included with your order. Unused. Only have a few.
