Utilizing our pure advanced MicroSealant, sandwiched between two removable protection layers, DoubleStick is sticky on both sides. It is perfect for use as a sill or gasket when installing patio doors or windows set deep in the framing. 3" DoubleStick comes in standard rolls 60 mils thick, 50' long, and 1", 2", 3", 4", and 6" wide.