(-early 1980s) motel. For a nominal fee, the mattress vibrates for a duration of time. Alternatively it is a modern bed which vibrates by use of an off-centre motor. It is controlled by electronics for varying time and amplitude settings and is used therapeutically to ease back pains or as an erotic aid. A waterbed is a flexible plastic mattress full of water. The plastic container needs a strong frame around it. Frames Bed frames, also called bed steads, are made of wood or metal. The frame is made up of head, foot, and side rails. For heavy duty or larger frames (such as for queen- and king-sized beds), the bed frame also includes a center support rail. The rails are assembled to create a box for the mattress or mattress/box spring to sit on. Types include: platform – typically used without a box spring. captain or storage – has drawers beneath the frame to make use of the space between the floor and the bed frame. waterbed – a heavy-duty frame built specifically to support the weight of the water in the mattress. (Mainly used on larger models) Although not truly parts of a bed frame, headboards, footboards, and bed rails can be included in the definition. Headboards and footboards can be wood or metal. They can be stained, painted, or covered in fabric or leather. Bed rails are made of wood or metal and are attached to a headboard and footboard. Wooden slats are placed perpendicular to the bed rails to support the mattress/mattress box spring. Bed rails and frames are often attached to the bed post using knock-down fittings. A knock-down fitting enables the bed to be easily dismantled for removal. Primary knock-down fittings for bed rails are as follows: Pin-and-hook fastener. A mortise or slot is cut vertically in the bedpost. Pins are inserted horizontally in the bed post so that the pins perpendicularly intersect the mortise. For example, if one looked in the mortise, one might see part of one horizontal pin at the bottom of the mortise and a part of a second pin toward the top of the mortise. Hooks are installed at the end of the rail. Usually these hooks are part of a plate that is attached to the rail. The hooks then are inserted into the bed post mortise and hook over the pins. Plate-and-hook fastener. Instead of pins inserted