"These Marvin windows have factory applied jamb extensions all around the window. I cut out the bottom piece so that I can install a 5/4 stool that matches the existing in the house. These 5/4 stools are 4-1/4” deep and the windows are sliders so there is int really a good way to attach to the window. I used this aluminium plate to index the Zeta from the bottom of the window. I was careful not to hit the myriad of staples that the factory worker who was clearly a machine gunner before his stint at Marvin. Once the scribing was done I figured out my offset for the Zeta fence and made all my cuts. I use the large biscuits to check my fit on a scrap. Using P14 tensos and wood glue makes a solid connection without any visible fasteners."