juice is correct the xe has what they refer to is the BOB system. Bolt Out of Back. The Xe allows you to remove the bolt with greater ease than a regular ion. Also with a regular there are many aftermarket parts for the Ion that you can buy to make a standard ion have a bolt out of back feature. there Fun guns to build. Think of them as the Honda Civic of paintball guns well back in there prime days any way. parts are a touch harder now to get ahold of then they were say 5 years ago.