Went 0 for 2 on a couple of Borofone models. 1st has a terrible channel imbalance (like 30dB) and the 2nd the right channel drops out about every 30-60 seconds. My advice would be look elsewhere. So far the best of the cheapie 2 piece bluetooth sets has been the syllable d9. The riversong air x2 isnt bad but sounds pretty compressed/recessed compared to the D9. I've got 4 more of the micro bluetooth sets coming (2 SmartOmi and a QCY and a TWS model) so maybe one of those will be a gem. Thus far, bluetooth utopia has been elusive to say the least.