These trigger point ones kick ass. I just use the cheapest ab roller I could find on amazon.

A foam roller is a more or less a big log of foam that can be used as a fitness tool or massage device. Placing the foam roller on the ground and rolling different muscle groups over it is very delightful. Using it on the legs and back can offer a great solo massage that is a great release after a hard workout.

I recently bought The Grid and couldn't be happier!

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I got this one and have used it every day since May and it hasn't fallen apart at all or shown any signs of wear yet. This is the first foam roller I've ever owned and it seems like a really good one.