A bearing housing for a gas turbine engine comprises: a bearing housing body having a bearing cavity defined therein and at least one of a built-in lubricant nozzle and a built-in scavenge hole defined therein and in fluid communication with the bearing cavity. One or more display devices may be connected to a system using a variety of communicative connections. The stainless steel substrate has at least one receiving recess defined in an outer surface and has a metallic coating formed on the outer surface. Thus, there is provided a nonaqueous secondary battery of excellent safety that can prevent abnormal heat generation due to a short circuit caused by burr, powder or the like piercing the separator.