Yes a bronze collet comes with the engine.
I just came back from Europe and bought my second Sirio S12 Evo 2 from the last batch........quality keeps improving.
I was present at the 1/8th 3rd round of the Spanish National Championship, and helped a private friend driver get a solid 4th place with a ballistic Sirio, just behind the podium pro-drivers.
I tell you these Sirio's are strong fast engines.....I would like to have seen this engine in hands of a pro driver.

AFM