Abstract: A horizontal sliding window comprising a glazed section and a screen section and means for opening, closing, locking, and unlocking requiring no more than five pounds of initial force to open, close, lock, and unlock the sections. In the preferred embodiment, the window is reversible before and after installation. The window comprises frame and sash members of aluminum, preferably 6063 T5 aluminum, or vinyl, preferably multi-chambered extruded vinyl. The sections slide on a stainless steel track and use rollers which are adjustable without removing a sash, preferably enclosed ball bearing rollers.