Do Integral LED fixtures experience voltage drop?

Integral Lighting fixtures that are equipped with our ultra-efficient 12vAC LED package operate with voltage from 8.0 volts to 12.5 volts. The ultra-low energy consumption of 0.25 watts to 4.0 watts virtually eliminates the voltage drop associated with standard incandescent landscape lighting installations.

How do I identify the new 2015 LED package?
Why does my transformer turn on, off and then back on?