Sight window (sīt win-dō) A simple device that allows one to see what normally could not be seen.
Typically associated with protecting the viewer while viewing.

Synonyms: sight glass, bullseye, viewport, indicator window, flow cell, insight

Rayotek Capabilities Overview



RSW ~ History:

Rayotek Sight Windows (RSW) is the end result of a natural evolution of business and technology that began at the parent company, Rayotek Scientific, Inc. (Rayotek). As an international leader in glass, sapphire and materials integration technology, Rayotek had received numerous requests to engineer long lasting, high-end sight windows for hostile environments. Though there are many companies that make sight windows, few, if any, could meet the rigorous requirements of Rayotek customers. And even more importantly, none that could provide the extensive engineering support Rayotek delivers.

After 15 years of making the highest quality, best engineered sight windows as a sideline, Rayotek decided to formalize its commitment to quality Sight Window production and Rayotek Sight Windows was born.

Although Rayotek Sight Windows began in 2006 as a department, RSW formally became its own entity in 2013 with the launch of its own web site and independent business address. RSW is now its own division, partnering with Rayotek, to form a powerful technology alliance.

RSW ~ Today:

Like Rayotek, RSW has a solid foundation in engineering and innovation. All products are designed, engineered, manufactured and tested at RSW-California with the goal of safety and sound engineering first and foremost. RSW has an extensive and diverse staff of engineers and technicians to support its Sight Window lines. You can contact us any time and, if not immediately, within 24 business hours be able to speak with an engineer who not only intimately understands how Sight Windows work, but most likely, how they will work with your application. Please see our Engineering Services page for more.

RSW also offers extensive FEA, simulation, modeling and testing expertise along with the equipment to support it. What this all adds up to is a powerful design and engineering team to help our customers:

  • Choose the best sight window for their application from our extensive array of stock sight windows, or
  • If a custom sight window is required, our staff can design and engineer the best sight window system for their unique application.

RSW ~ The Future:

By design, RSW is a constantly evolving company. Our philosophy is: in order to meet our customer’s needs we must always stay ahead of our customer’s technologies. What does this mean for you? RSW commits a significant portion of its annual budget to glass and sapphire sight window and pressure system R&D, including:

  • Studying technology trends in benchmark industries, such as: commercial electronics, semiconductors, aerospace, petroleum, deep sea and energy production.
  • Continuous Improvement (CIP) of RSW technologies. Because our customer’s needs are constantly evolving, then we must be one step ahead of them!
  • Developing new Sight Window and sealing technologies to meet evolving customer needs.
  • Keeping our finger on the pulse of, and anticipating customer needs by way of dialogue with customers and potential customers.


Rayotek Sight Windows is the last word in Sight Window technology.
We would like to be your first stop for all your Sight Window and pressure system needs.

Rayotek is SAE AS9100D & ISO 9001:2015 Certified and maintains an exceptional Quality Management System. All incoming and outgoing products undergo rigorous inspection processes by our highly trained Quality Assurance Department.

  Download AS9100 Certificate