A "next-generation" Glock 17, determined by the checkering around the front and rear straps of your pistol grip and set off guard A mid-lifetime update into the Glock pistols associated the addition of checkering within the front strap and bring about guard and checkering and serrations towards the back strap. https://glockswitch20740.ourcodeblog.com/37427534/the-2-minute-rule-for-glock-17-switch