A window vent stop for use in a sliding sash window assembly or a sliding door assembly. The vent stop has a housing adapted to be disposed in a recess in the non-movable sash member. This housing includes a cavity with a bottom plate therein. The tumbler has at least one pivot for pivotally securing the tumbler to the housing for movement between an extended position, to prevent movement of the sliding member and a retracted position, to allow movement of the sliding member. Also within the housing is a spring for biasing the tumbler. The housing has one or more flexible members extending from the end walls of the housing that secure the housing to an opening in a window sash when a portion of the window sash ispositioned between the underside of a lip on said housing and the flexible member.

A sash window fastener includes: a latch assembly; a sash lock assembly mounted upon the meeting rail; and a stop member mounted to the master window frame. The lock assembly includes a pivotable cam to engage a keeper on the master frame to lock the window, and a pivotable follower arm. The arm interconnects with the latch assembly within the meeting rail, so cam rotation that drives arm rotation also causes translation of the latch. The cam may occupy: an extended position to secure the cam to the keeper, with the latch engaging the master frame to prevent tilting, and being positioned below a protrusion on the stop member to redundantly lock the window; a first retracted cam position permitting sliding of the window; and a second retracted position permitting tilting of the sash window. Additional protrusions may be used on the stop member to serve as vent stop positions.

A removeable window control device in the nature of a vent stop including a housing having a peripheral flange defining an opening, at least one channel, and a pair of opposingly oriented sockets, a bolt including at least one leg, wherein the leg further includes a protuberance and a tab, a cover including a lateral side of substantially similar shape and size of a lateral side of the housing, wherein the cover further includes a pair of opposingly oriented pegs and at least one channel, and a resilient member engaging a conduit defined in the bolt and a back side of the housing to urge the bolt along the channels formed in the housing and cover towards the opening defined by the peripheral flange of the housing. The vent stop is preferably inserted into a frame of a window.