Most wheelchair upholstery is based on one of two designs, Invacare and Everest and Jennings (E&J). Some wheelchair manufacturers use designs from both and some have their own designs (Quickie for example). In most cases having the dimensions can save you from worrying about knowing the brand and model.
Replacing wheelchair upholstery is one of the easiest and most important things you can do to improve the comfort and safety of your residents. Stretched or torn upholstery is unsightly and can cause skin tares to the user and staff.