The Precision Weld Series 400 by Okna Windows are an excellent value when comparing windows from companies such as Harvey, Alside and Mercury Windows. The Series 400 is Okna's mid range window line with a high-end look and rating. The 400 series also has triple weather stripping and a low air infiltration rating out performing most high- end windows on the market at an affordable price.
- The series 400 has a beveled two point welded master frame.
- Triple weather stripping on sashes.
- Air infiltration rating of 0.05, still one of the lowest in the industry.
A window consisting of two sashes operating in a master frame where both the upper and lower halves slide vertically past each other and both tilt in for cleaning.
A window consisting of two or more sashes which operate by sliding horizontally past each other.