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OKNA 400 Series - Double Hung Windows

The OKNA 400 provides leading-edge window performance, without the price tag others charge for their more modest windows.  With air penetration protection that's 400 times more effective than the industry standard, and a world of customization options, OKNA 400 Series Double-Hung windows are sure to exceed your demands.

Precision Weld Double Hung Windows

OKNA 400 Series Windows

  • Precision Weld
  • Ideal Windows for Every Home and Budget
  • Heavy duty frame with precision welds for increased durability
  • Triple weather stripping ensures even greater energy-efficiency
  • Designed to minimize noise and friction
  • Innovative condensation resistance and thermal performance
  • Smooth gliding open & close features
  • Tamper-proof locks and hardware offer increased peace of mind
  • Low air leakage rating
  • NFRC U-Factor: 0.28  Air Infiltration: 0.05  Solar Heat Gain: 0.30
Overview - Options & Accessories - Performance
Precision design and a welded 3.25" mainframe beveled curves give the exterior a clean and sophisticated look, while providing years of protection from rain and rust, strong winds, excessive sun and frequent use.   Push button latches on a spring-loading sytem, allow you to open your 400 Series windows all the way for maximum breeze, or just slightly opened when wanting both ventilation and added security.

Double Hung Window Corner


Double Hung Window Latch


Screens on the OKNA 400 Series are built to be effortless, safe and durable.  They also give the windows a clean and solid appearance, with highly-resistent mesh.   The ONKA 400 Series' intergrated lift rail system boosts both appearance and smooth functionality.  Yet another innovation that makes these windows a favorite in WNY.

Double Hung Window Heavy duty lift handle


Double Hung Window life rail


Water drainage is mess-free and streamlined for optimal efficiency, thanks to the 400 Series unique 1-piece sill slope.  Say goodbye to leaks and standing moisture!   If you're looking for the ultimate in window insulation without compromising style or performance, the OKNA 400 Series Deluxe windows can be ordered with optional foam insulation.  Keep heat & cool air in or out, in any season.

Double Hung Window water drainage


Double Hung Window Insulated