PurAhtletics 65cm Exercise Ball. It's good for sculpts, strengthens & tones. Benefits are strength, flexibility, balance & posture. You can work on tone & sculpt your shoulders, arms thighs and abs. These exercise balls for working out are quick to inflate/deflate for easy use. Just pump with air using the straw provided to inflate or remove the plug to deflate after use. Use this yoga ball for exercise and beyond! Stretch before a HIIT session, build core strength and flexibility on the mat, or place behind you while sitting in a chair for lumbar support.