Hinged windows are available in a variety of standard designs. A simple hinged window is essentially a fixed window with the appropriate fittings to enable it to be hinged directly to the cabin wall. A more popular type of hinged window incorporates two frames, one inside the other. The inner frame is then hinged to the outer frame, along with any stays, catches or other fittings. The outer frame can be mounted directly to the cabin wall. A further type of hinged window is the multi-hinged window which incorporates one or more opening vents at the top of the window. The whole window is also hinged to open. Three standard hinges are available. The continuous hinge comprises of interlocking sections which form the hinged edge of the window. The advantage of this lies in its waterproof properties. This kind of hinge requires that any adjacent corners are square. The friction stay is a very popular choice, which enables the window to remain open in any position, alleviating the need for any other type of stay. As with the continuous hinge, any adjacent corners must be square. The loose hinge is a simple type of hinge which is usually used with some form of stay to keep the window open when required. A hinged window can incorporate one of several types of catch. A casement handle is a popular choice, whilst the security catch is a more industrial option.