樞軸定位器

Finally got to try this during a longer session and the high-density foam core really does help reduce fatigue. My partner and I were both surprised how much longer we could last without needing to adjust positions.

The high-density foam core really does hold up — I used it for over an hour and didn't feel that usual ache in my lower back. It's firm enough for support but still has just enough give to stay comfortable. Honestly didn't expect a piece of foam to make this much difference.

Wasn't sure about the wedge shape at first but it's made longer sessions way more comfortable. The foam is soft enough to sink into yet holds me up fine, and my knees stopped aching halfway through.