Refractive Index:
1.800 and Higher


ULC witness samples come with a Refractive Index (Nd) of 1.400 and higher. They are made in America, offering high quality at an affordable price. Characteristics of our witness samples include:

  • Many Popular Glass Types: Select from a large assortment of the most popular glass types.
  • Laser Etched Part Number: No more problems identifying material. The part number is laser etched on the edge and can be cross-referenced to the material type.
  • Inspected per MIL-PRF-13830B: Each sample is inspected for surface quality.
SKU: UL-WS-013 Category:

Additional information

Weight 0.03 lbs

DEDF805254, LASF-N15, LASF-N9, N-LASF41, N-LASF43, N-LASF44, N-LASF45, N-LASF46A, N-LASF9, N-SF57, N-SF6, N-SF66, S-LAH52, S-LAH53, S-LAH55, S-LAH58, S-LAH60, S-LAH65, S-LAH71, S-LAM66, S-NPH1, S-NPH2, S-TIH53, S-TIH6, SF-57, SF-6, SF57HT ULTRA, SFL-57


25.00mm ±0.20mm


3.00mm +0.20mm/-0mm


< 1 wave @632.8nm

Surface Quality



0.50mm ±0.13mm FW x 45°

Clear Aperture

80% min