Made by Lift Support Technologies
10mm Rod x 22mm Cylinder
SL28-XX
Extended Length 30.91
Compressed Length 17.13
Stroke Length 13.78
Above dimensions in (Inches)
Force (lb) 30-180
10 mm Socket-Composite
SL28-XX-1
Input force for XX so yours has 30lb of force
This company appears to custom make the supports
Here is the same dimension strut by different company price appears to be average for that support. You can use the dimensions above to shop around. As the website states you should replace these in pairs if it has two.
http://www.autopartsbylou.com/lift-supports-product.php?item=60092