features two ball bearings non-rising removable pin with button tip and plug 5 x 5 (127 mm x 127 mm) and 4-1/2 x 4-1/2 (114 mm x 114 mm) bb1279 available with two different leaf sizes 3-1/2 x 3-1/2 (89 x 89 mm) bb1279 available with reversible hole pattern for use on medium weight doors or doors requiring medium frequency service