M140 Spring

Details

After 6 months try and error, we finally made the most “colorful” spring which is more beautiful than anyone else. (So does the performance)
(The color is not painted. It is hard-coated by special process.)
Calculated carefully by computer and test by 100000 times punching.
Our spring has been proofed that the length and force are still consistent. (See here)

We just want to proof that our spring is not just a “spring”. It is a MadBull spring and it is “colorful.”

Other features:
•Consistent >100000 shotsl
•Non-liner design (calculated)
•Color coating to reduce effects from environment
•Design & Made by experienced engineers.
•Premium quality German piano wire