The cam lock and keeper mechanisms keep the window sashes together when locked.

Capillary tubes are small hollow tubes that penetrate the spaces of glass and allow pressure to be equalized at all times.

A casement window has an outward side opening with hinges at the top and bottom of the frame.

The center of glass U- and R-values are measured from the center of the glass to 2-1/2" from the frame.

The condensation resistance factor measures the effectiveness of a window to reduce condensation. A higher number means better efficiency.

Energy transfers by means of conduction between two materials with direct contact.

Heat transfers via convection by the circulation of currents from a warm surface to a colder one.

A coved exterior is an arced extension of a window on the outside of a house.