I wore each for a few hours respectively. However, the mountain bike is heavier and the odd angles make it difficult to hold without putting a lot of stress on the frame. When you are walking or standing they are very comfortable but when you are sitting or resting your feet on an ottoman etc. 5 hours if I play it safe. I needed to remove the plastic caps from the end of the side supports for the rail to fit "upside down" and the bolt align to secure. I am returning these and ordering the M8/W10. The slippers were EU size 40 and was really small. I’m so glad I just decided to treat myself and buy it along with the headset. I wear a 14/16 and I wear a 40DDD bra. Always get them a size larger than what you wear.