Window Stays ASSA ABLOY Window Stays have a proven track record. With our patented friction bearing and unique "pull in" features, you will have control of the opening angles of your homes windows. Friction StaysASSA ABLOY offers a full premium range of 4-bar Friction Stays to suit aluminium windows. Restrictor StaysASSA ABLOY offers a range of restrictor stays for those with safety and security in mind. Restrictor stays provide safe ventilation in the home for timber or aluminium windows.