Actually, this was supposed to be a review of the SMH10R but I guess I messed up and placed it for the slim speakers which I also bought. I bought this model because of its low profile design even though I ride a large R1200GS adventure bike. I feel that it is less likely to catch on something and twist my neck in an accident. The battery is small enough to mount inside the helmet to the side of my mouth so the only part that is externally visible is the low profile control unit which is almost invisible on my black and white helmet. The fewer people know I have it the better in my mind. Installation on, and in, my helmet was pretty straight forward. I bought it with the additional smaller speakers that were reviewed as sounding better than the large ones that come with the unit. I haven't compared the two so I can't testify to the difference but the unit and small speakers sound very good. It paired easily with my LG android phone and works flawlessly with it. I did have to go back to the quick start card a few times to memorize the different operational instructions. Each of the 3 buttons performs a variety of functions depending on how long you hold it. The unit gives you feedback in the form of beeps to assist in knowing if you're accomplishing the desired task. The phone function performs extremely well with the mic mounted directly in front of my mouth in my Arai helmet. I am about to pair the unit to the Garmin Zumo 660 I just bought so I can't comment on that operation yet. Nor have I tried to pair it with another headset yet for bike to bike communication. The battery has lasted all day playing music on some long days of riding. I am very happy with this product so far. Oh, and with Amazon Prime it almost arrived before I ordered it.