The MyPillow® Bolster Pillow stays cool and provides perfect support under the knees while sleeping on your back. Provides pelvic support if placed between the knees while sleeping on your side. Provides lumbar support while seated at your desk or in the car. All MyPillow® Specialty Pillows are filled with our patented, medical grade, nonallergenic fill. Fully machine washable and dryable. 60-day Comfort Guarantee and a 10-year Warranty. 6" Round x 18" Long.