Bands are straps for tying yoga mats, which are actually yoga mats, yoga balls, yoga bricks, and tensioners ... Yoga mats are practical things, so I won't go into details. Yoga ball is mostly the practice of waist, abdomen, legs and arms, and it works well with practice. Yoga bricks are used by beginners to correct or assist yoga. Stretcher, for forearm, biceps, butterfly sleeve, shoulders, back, chest, abdomen, thighs, are all useful, but this is a professional, most people may not use it, the human body structure is the same, so exercise is regardless of age. I am a national professional fitness coach. Welcome to consult.