Short for "Companion Can", the C-CAN was originally designed as an add-on suppressor for the Companion flashlight gun produced by Ares Defense Systems.  It works very well on any firearm with a threaded muzzle which fires .22 LR ammunition.  The suppressor is constructed of 4130 DOM tubing and uses the same stainless and aluminum internals as the SIRIS.  It has a parkerized finish and laser engraving, and quality is superior throughout.  The thread at the base is 1/2-28 UNEF. Overall length is 5.50 inches and the OD is 1.00 inch.  Though maintenance is not required, both endcaps unscrew should there ever be a need to gain access to the internals.

The Companion barrel adaptor is made from 4140 steel barrel blank, and is threaded 1/2-28 UNEF.  It is rifled, unlike the Companion's stock barrel, and it has a parkerized finish.  Price of the C-CAN is $225, the Companion barrel is $40.