About KÖSTER
KÖSTER makes products that preserve daylight and views while reducing solar heat. Its mirror-optic daylight louvers address light and heat in one system.
KÖSTER is in Fairfield, Iowa. Polo Altynski-Ross is co-founder and chief executive officer. Stephen Ross is chief operations officer.
Funding Rounds (SEC Form D)
| First sale | Filed with SEC | Amount sold | Investors | Avg. check | Terms | Filing |
|---|---|---|---|---|---|---|
| Sep 12, 2026 | Oct 21, 2026 | $500,000of $1.0M target | 12 | $41,667 | OptionsRule 506(b) | Form D ↗ |
First sale is the date the first investor in the offering committed to invest. Companies must file Form D within 15 days of that date, so filing dates run later.
Why Investors Backed KÖSTER
KÖSTER sells mirror-optic daylight louvers. Its investment case centers on reducing solar heat without losing daylight or outside views. The installed base shows the system has moved beyond a concept.
The problem it targets
KÖSTER frames the problem as getting more light with less heat. Its louvers aim to retain daylight and views while cutting solar heat gain. This goal combines visual access and heat control in one product.
What the product does
The mirror-optic louvers reduce solar heat gain by up to 80%. They are designed to retain daylight and the view at the same time. The product combines light control and heat reduction in one system.
Progress so far
The louvers have been installed across more than 6.5 million square feet. Those installations span 11 countries. The figures describe both physical footprint and geographic reach.
We wrote this summary from public statements by KÖSTER and its investors. It is not investment advice.
Leadership Team
Executive officers and directors listed on KÖSTER's Form D filed Oct 21, 2026.