I had purchased these without realizing they where 250 Ohm. Since my DAC can't power them, I'm selling them

The Beyerdynamic DT 770 PRO headphones are designed to offer you all-day comfort and superb sound clarity. Employing bass reflex technology, these Beyerdynamic headphones offer you rich and powerful bass with exceptional quality. You can adjust the headband of these over-the-head headphones to suit the contours of your head, thereby making it supremely comfortable to wear for long hours. Moreover, the single-sided cord in the Beyerdynamic DT 770 PRO reduces the tangles and simplifies exchanges. Featuring a frequency response ranging from 5 - 35000 Hz, these over-the-head headphones enable you to listen to sounds with amazing sharpness. As these Beyerdynamic headphones come with a 3.5 mm connector, it is compatible with most of the portable media players, mobile phones, PCs, and laptops. What’s more, with a sound pressure level (SPL) of 96 db, these Beyerdynamic headphones guarantee high-fidelity sound output.