Seiler Instrument Company

Seiler Instrument is the Original Equipment Manufacturer (OEM) of optical fire control equipment used by the United States, Canada and international militaries. It is responsible for the systems used on all United States howitzer and mortar systems. It also manufactures related test fixtures and test equipment required for repair and calibration.

Seiler also performs turnkey inspection, repair, overhaul and refurbishment of artillery fire control systems including those used on all existing United States howitzer systems worldwide.

Seiler’s capability encompasses a broad range of precision optical instruments including periscopes, telescopes, target collimators, boresights, borescopes, gunsights, dioptometers and tripods. Its product portfolio comprises over 50 different equipment types. 

In Canada, Seiler’s instruments are used on diverse generations of weapon systems such as the LG-1 (GIAT) & M-777 (BAE) and legacy systems such as the C1 and C2 howitzers.

Seiler has comprehensive in-house capability and equipment for manufacturing and assembly, as well as testing and inspection in accordance with MIL-I-45208 and MIL-Q-9858.  

Kaycom has represented Seiler Instruments since 1988.

Seiler's headquarters are located in St. Louis, Missouri, United States.