Certain VM700A and all VM700T instruments are eligible for upgrades that add new measurement capabilities. The limitation for the VM700A is that only "Turbo Upgraded" VM700A instruments are eligible. VM700T units are identified by both the VM700T nameplate and the power up screen indicating VM700T. A "Turbo Upgraded" VM700A instrument can be positively identified by an Option TB tag affixed to the rear of the instrument and by the power up screen display indicating "VM700T".