Ventadome V2092SP-25 Birch New Style Non-Powered Lift mechanism provides a smooth operation and eliminates chatter; 14.25 inch x 14.25 inch rough opening The slide mechanism has more surface area contact Making the guide bar stronger and allowing better distribution of stress 2-piece snap-out screen easily detaches for cleaning The ceiling garnish and crank handle remain in place: no screws to lose; 2-piece removable Birch White screen frame