A Hormann superior genuine spring loaded roller assembly with safety latch to suit current Hormann canopy garage doors manufactured from April 2002 onwards. Post April 2002 garage doors can be identified by having a single overhead spring. 
 
Sold singularly in either left or right-hand.
 
This is a genuine Hormann product to suit the following Hormann part number:
Left-Hand: 1891013. 
Right-Hand: 1891014
 
Tip: To determine if you need left or right-hand spares, stand inside your garage and look from the inside out.