The Spring Kit includes our Strongest Spring, T-Handle Wrench, and Replacement Screw. 
 
Assembling a mini - Notes 

The piston only goes in one way.  

See how everything fits together Without the spring first.  Its easy that way.  

You want to be careful with the spring.  Safety glasses are recommended when working with springs.  Only compress the spring inside the body of the mini.

It's easier to compress the Piston pushing down against a solid surface like a workbench than just using your hands.  

Once you understand how everything goes together without the spring install the spring and screw in the long screw from the back of the Body into the Piston.  The screw goes right through the Spring. 

When you are done the mini should be 2.9-3.0 inches long as shown in the photos.