Description 24 V.D.C Fail Safe Electromagnetic Slide Track Designed To Be Compatble And Tested With The Arrow Architectural 324vp Cam Action Door Closer ( Included ). This Electromagnetic Slide Track When Installed Will Hold The Door Open And Release Automatically In The Event Of A Fire When Installed As An Integral Part Of A Fire Alarm System Or A Manually Switched Supply. Construction The Electromagnetic Track Is Uniquely Designed By Arrow Technical Details: