Work out the knots after a long day of hiking. At just 45 grams (about 1.7 ounces) the Cork Massage Ball is perfect way to roll out your muscles after a long day of hiking. Use body weight to roll the ball into the sore muscles after a day on the trail and you will feel the tension melt. Perfect for feet, shoulders, calfs and lower back. Approximately 2.5" in diameter it will pack easily in the corner of you pack.