Confirm the exact configuration
Use the manufacturer part number and model code—not appearance alone. Connection, size, material, voltage, pressure, seal, and control options can differ within the same product family.

Thorlabs
The Thorlabs LK1431R-A is an f=-75 mm, Ø25.4 mm BK7 plano-concave round cylindrical lens with a lifecycle spanning from its November 5, 2008 release date to its November 21, 2009 discontinuation date. This discontinued component has an official replacement model designated as the LK1431RM-A. Submit the exact part number, quantity, and application requirements to request a quote.
Industrial and obsolete parts are priced per enquiry: the final price depends on available stock, condition, quantity, and your delivery destination, so a fixed list price would be misleading. Request a quote and we confirm current pricing, lead time, and sourcing options — including hard-to-find and discontinued Thorlabs references — within one business day.
For a faster response, include quantity, condition, and delivery destination.
Verified configuration
Engineering context
Use the manufacturer part number and model code—not appearance alone. Connection, size, material, voltage, pressure, seal, and control options can differ within the same product family.
Provide quantity, delivery country and ZIP/postal code, required condition, target date, and photographs of the existing nameplate when available.
Our sourcing response is prepared against Thorlabs LK1431R-A. Final compatibility remains subject to the machine manufacturer’s requirements and complete application data.