Precision Weld 400 Series

A practical, versatile replacement-window choice.

The OKNA 400 Series offers energy-conscious, low-maintenance vinyl construction in standard and custom sizes, with a useful selection of glass, color, grid and hardware options.

OKNA Precision Weld 400 Series double-hung windows installed in a living room
OKNA Precision Weld 400 Series double-hung windows. Product photography courtesy of OKNA Windows.

What makes the 400 Series worth considering?

The 400 Series is designed for buyers who want a dependable replacement window with choices that can be tailored to the home. Its thermally welded vinyl construction, insulated glass options, weatherstripping and reinforcement are intended to support comfort and everyday operation.

Good fit for: homeowners replacing older windows, rental-property projects and contractors who need a straightforward product line with common configurations.

Available window styles

  • Double-hung windows
  • Horizontal sliders
  • Picture windows
  • Casement and awning configurations
  • Basement and specialty shapes, subject to availability

Choices that shape the final window

Ask about double- or triple-pane glass packages, Low-E glass, gas fills, interior and exterior colors, grid patterns, screens and hardware selections. Availability depends on window type, dimensions and current manufacturer offerings.

Before requesting a quote

Count the openings, note each window style and gather preliminary width and height measurements. Photographs are helpful when the existing frame or trim is unusual. Final order dimensions should always be verified before manufacturing.

Read our preliminary measuring guide →