The V4 is a more recent version. It is used as a backup blaster, and is not as powerful as later versions (The V5 (destroyed), V6 (current), and prototypes V7, Alpha and Omega). Unlike the others, it was not destroyed in battle, and can be called back at any time using Alex's Tech Remote. It has all the Form Disks Alex had collected up to the point the Proton Blaster V5, as well as all the data. It does not have the more recent Disks, such as the Hammer Disk, Drive Disk and Whip Disk.