what is the vr1 resister on my straighteners ?

VR stands for Variable Resistor

VR1 stands for Variable resistor number one in the circuit - it's also very probable that there is only one.

On your straighteners - you do not say the brand or the model - the VR may well be the little temperature wheel you can see in this video..

https://www.youtube.com/watch?v=KMLphjVT1XI

But that's just a guess...

Good luck...
May 2015