I used these hybrid pads to retrofit my decades-old high-impedance AKG K240 'phones, currently being driven by an XDuoo TA-01B DAC/amp. While the original pads were miraculously undamaged after all this time (I am careful with my things), the leather was stiff and the foam way past its expiration date.
Installation was a snap compared to getting the old, stiff ones off, the vinyl was so shrunken and hardened; I was almost at the point of cutting them off when I succeeded.
The new ones popped right on after some pre-stretching and some help from a popsicle stick; I found that once installed, rotating the pads helped to get them quickly centered on the ear cups. Mine seemed to fit best with the seams facing downwards. There are no flaws in the fit and finish and they were well packed for shipment.
To my ears the sound quality was largely unaffected, if not somewhat improved, by the change, and the comfort and sound isolation of an old favorite was restored.