Sojoy iGelComfort Coccyx with Beautiful Buttock Gel and Memory Foam Seat Cushion for Back Pain Relief, Tailbone Support (17x2.8x13) Ultra-soft, ultra-strong, solid rubber-like Gel and Memory Foam material. Breathable gel stays cool during use! Engineered &amp; designed for human comfort threshold, adjusting to any individual&#039;s body shape or weight. All of Sojoy&#039;s gel cushion products are safe for traveling on plane and complies with FAA regulations.