My VF3000 came with a braided oil supply line.
you can buy them at a plumbing&heating supply store I saw it at Blackman plumbing.
They came in 3ft or 5 ft lengths.
check out the pictures I posted "firing the VF3000 on oil"firing the Harman VF3000 on oil
I looked into getting another flex line because the oil gun height (off the floor) is about the same level as the oil level in my oil tank when it is 1/2 full so it may not flow by gravity from the tank to the oil gun.
So I was thinking I might need to add a return line from the oil gun back to the tank.
I am only burning coal right now so It is not a problem .
If the price of oil stays low ($1.48/gal [cash]) I will probly switch to oil for the summer and then I might need to add the extra return line.