As someone who regularly exercises and stretches, I treasure my foam roller:

I didn’t even know what foam rollers were until last year, and only discovered how they are supposed to be used this year. Prior to that, I would always have sore muscles for days after practises and working out. 

Despite its simple design, foam rollers are quite effective. Mine is made of a hard foam and textured with bumps and grooves. It’s also super light to carry and is this lovely grey colour. To use it, one simply rolls the sore area on the foam roller. It hurts, but in a satisfying, good way. A few rolls are enough, and the next day, my muscles will feel significantly better. Since getting this roller, I haven’t had to deal with painfully sore muscles from working out. Even after an intense workout, the soreness will last at most one day. 

My only complaint is that it picks up dust easily, but a quick rinse or wipe-down solves that problem.