Masonry opening

Space in a masonry wall left open for windows or door.

 

Mortise-and-tenon

Strong wood joint made by fitting together a mortise in one part and a matching projecting tenon in the other. Used as a corner joint in Pella sashes.

 

Mullion

Wood, metal or vinyl part used to structurally join two window or doors.

 

Multipoint Lock System

Pella’s locking system that secures the door at multiple points for added security.

 

Muntin bar

Small bar that divides window or door glass. Better known as a grille (or windowpane divider).

 

Non-decorative glass

Glass with no embellishments; clear glass.

 

Obscure glass

Glass with a textured surface. It provides low visibility but allow in natural light.

 

Out-swing door

Door that opens to the outside rather than to the interior.