Manufacturer's part #01 LAM 555/078 (broadband AR coated for 450-700nm). Original unit price: $82.00. Made of N-SF8 glass, design wavelength is 546.1nm. Clear aperture of 36mm, center thickness is 6mm, edge thickness is 5.2mm. Centration is 3 arc minutes. Edges are .25-.50 bevel. Manufacturer's companion doublet for this lens: 01 LAO 555. Aplanatic lenses are free of spherical aberration and coma.