This listing is for a solid aluminum Grey Anodized Dummy 12 Gram CO2 cartridge.  This dummy CO2 has two 1/8" NPT ports, one on the end and one on the side 1.5" from the back.  It is modeled after a real 12 gram CO2.  The overall length is 3.25" and the diameter is .73"  I have included one male 1/8" NPT plug so that you can plug the port you do not intend to use.  This dummy CO2 is normally used to convert a stock class paintball gun, or pistol into a constant air paintball gun, so that you don't have to keep buying those expensive 12 grams.  It is best used with a remote line.  That is how I recommend using it.  Please email if you have any questions.

Don't risk drilling out and tapping one of your empties. That is HIGHLY dangerous.  There will be less than 1/16th of an inch of threads, and your fitting is very likely to blow out, possibly causing injury.  This Dummy CO2 has FULL LENGTH 1/8" NPT threads, so it is MUCH safer.  If you are picky, depending on the type of fitting you thread into this dummy CO2, you may or may not have to tap the threads a little deeper to get your fitting to sit at the height you want it to when it is tightened.

These things are getting VERY hard to find in the last couple of years, so get yours before they are gone.