UR242 With High Impedance Headphones?

What’s the highest impedance the UR242’s headphone jack can properly push? I’m looking at getting a pair of the Massdrop x Sennheiser HD 6XX Headphones (which are essentially the same thing as the Sennheiser DH650) which have a 300ohm impedance.

I’m new to high impedance headphones and keep reading a amp is needed to drive them properly. I’m not sure if that’s something I need to add to my UR242, of if I would end up needing a separate DAC and Amp to get a proper sound out of them.

Hi
I use Sennheiser HD650 and 660s with my UR22 mk2, no problem whatsoever.