Pressure comes from strap tightness and posture, not just speed. Keep straps loose (don't pull them tight), wear thin clothing, don't lean back against the sofa or chair, and start at speed 1. How can I avoid this? The neck massager feels weak even when fully charged. Is it defective? Please check and fully charge it (about 3 hours), tighten the adjustable back buckle/strap for firmer contact, and use speed 2–3, pull the shoulder straps tighter, or lean back against a chair/sofa. The red LED lights are behind black cloth — do they actually reach my skin? The 660nm are visible red light while the 850nm are invisible — you won't see them glow, but both emit through the designed opening onto your neck. The fabric is for comfort and diffuses stray light; it does not block the treatment area.
