Originals were “contractor” windows so the replacements made an immediate difference on many levels: better temperature inside; we can leave south-facing blinds open without feeling the sun’s heat as we did with the others. Ease of use, delight of their functioning, solid & well-insulated manner in which they were installed add to our tremendous satisfaction. Any photo from here – while looking excellent in & out – will not tell entire story of the impact we sought (& got) with product, installation (on-time, respectful, pleasant, flexible installers), & on-top-of-it communication from Zen management.