ZiPTM can be attached to your rifle or shotgun platform with the ZiPSBR Rail. * ** Note: SBR stands for a special classification of weapon (In this case a pistol) when transformed into an SBR- or Short Barreled Rifle. * As such, purchase of a rail or a stock does not require an Approved ATF Form 1, however, * USE OF THOSE COMPONENTS while in combination with ZiPTM (attached to another platform) * Does Require an Approved Form 1 for legal use.