Schlegel Hydrosill threshold (anodized bronze aluminum) is 4-9/16″ wide for 1-3/4″T doors. Extender is used to accommodate brickmould and wider jamb.
Brickmould may be various thicknesses (our standard is 1″) depending on the specific installation. You must include the thickness of the brickmould in determining the appropriate width of the extender. Extender should not protrude beyond the brickmould whenever possible.
Threshold depths available:
1-3/4″ thick doors: 4-9/16″, 5-9/16″, 6-9/16″ and 7-9/16″.
2″ thick doors: 4-13/16″, 5-13/16″, 6-13/16″ and 7-13/16″
2-1/4″ thick doors: 5-1/16″, 6-1/16″, 7-1/16″ and 8-1/16″