Special laser optical filter 620nm bandpass (unknown brand) Description: no longer needed in my lab. sEEM Edmund Optics, Newport or Omega brand. I have not full information (only bandpass), but you may know enough of it given this information. Tests done with "mirror side" facing light source. Measures: Mount is exactly 1" 25,4mm (filter a bit smaller to fit in mount). Thickness is 0,246" (6,24mm). Catalog number and other info: D.O. #15-20450 INQ 3-5 (this last number might be the cut-on cut-off tolerances in nm) Straight light-through behaviour (0º angle): LED HALOGEN light source show light RED color. Edge-on light-through behaviour through HALOGEN light source (around 80º angle): light RED color. Weight: 5,8gr. Condition: filter shows some aging in the light-in side mirror side (outter portion only). No scratches or haze. I would say GOOD-EXCELLENT OVERALL condition. Delivered in original package. Shipping: Remember I combine shipping.