Replacement Door Wheels for Sash Windows These are replacement door wheels for sash windows. We recommend replacing them if the sash window becomes difficult to open and close. These door wheels are designed to be universally compatible for replacing door wheels in many sash windows. They are for both left and right sides, so you need two door wheels per sash window (four for a sliding window). These are newly designed universal adjustment door wheels for replacement in renovations. With a frame height of only 18.5mm and a thickness of 9mm, they are extremely compact, yet offer sufficient smoothness and durability. Installation is done by attaching to the side of the lower sash frame, and the wheel height can be easily adjusted with a screwdriver from the sash end. Material: Frame: SUS430 Wheel: Polyacetal, oil-impregnated Adjustment screw: SUS430 Spacer: SUS430 Specifications: Maximum sash weight: 30Kgf / 2 pieces Durability: Equivalent to 50,000 open/close cycles Height adjustment range: 20+3.5mm ※Price is for two door wheels.