Electronic paintball guns operate on lower pressure, are typically quieter, lighter and usually shoot faster than mechanical guns with a shorter trigger pull. They do require a battery, often require compressed air (CO2 can mess up the gun, so avoid it if your gun's manual says to) and don't hold up to water nearly as well as mechanicals. They can make good primary guns or make a fun change of pace for certain games. If you've never tried one, now is certainly a cheap time.
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