Purchased by my partner who wanted to see and try (she has "heard" talk on forums dedicated to back pain) I use it for a month and it works, actually less pain and fewer painkillers especially seals. The first contact is strange, the pellets are very aggressive when you put a finger on it, but it's based on the principle of the carpet so fakir once lying is good, however the first minute (at least for me) is a bit unpleasant, after all is well, massage sensation (much like the impulses created by electrodes that Emploi physiotherapists) in concentric circles, then a warmth feeling. The manual recommends at least 20 minutes, perso I sleep on it (that to this effect on me) and I wake up because I have to move at some point, and the carpet become "aggressive" like a cheese grater !