WASHINGTON — (WPXI) – The Secret Service will use bulletproof glass to protect former President Donald Trump during outdoor campaign events, NBC News reports. According to the report, that ballistic glass is already available to sitting presidents and vice presidents. The glass is transported using military aircraft when the president travels. Not every event will require ballistic glass, but NBC News reports it is likely to be used whenever there are issues at specific sites or there are needs for added security. The addition of ballistic glass is one of several security measures being used to protect Trump after the assassination attempt on him in Butler on July 13. Trump has not held an outdoor campaign event since the attempted assassination.