Accordion Mount Door Kits allow strips to turn and retract off to the sides of an opening. The strips collapse into 10% of the door opening width. Strips are 12” wide and overlap a standard 4” . How to order When ordering sliding strip door kits the track system is twice the width of the opening (I.e. If the opening is 5ft, 10ft of track is supplied). Sliding Strip Door can be configured as bi parting and or single sliding (all one way).