Kewanee C400K 16 inch Vinyl Basement Insert, Dual Pane Glass

Part Number: 105016
Price: $187.50
C-400K Vinyl Basement Insert - Kewanee Replacement with Expander / Adaptor

The Columbia Series 400A vinyl basement window is an insert with insulated glass.
Maintenance free and energy efficient
Easy 1-minute installation.
Needs no tools to install; uses high tensile steel spring clips to secure the insert in the opening.
Expander allows for use in most concrete basement walls with poured-in-place steel Kewanee buck frames.

Available in white vinyl only.

For standard 31 x 16 inch basement windows.

Fits in buck with 7/8 to 1 inch drop-down (see third image).

The Kewanee buck is slightly different than Columbia, and the expander is added to the bottom of insert. The expander creates a thick leg that fits into the crevice of the Kewanee steel buck frame.

Priced and sold each.

Resources:
Article: How to Replace Basement Window Inserts
Video: How to Replace Basement Window Inserts