It excels at its intended purpose. I opened the box and went to put on the eyebrow trimmer and it was too small. For the price these oversights are easily forgiven. But the real reason for my damning review is that within just three months or so its malfunctioned for no discernible reason. I bought four adapters for four bicycles to attach the Niterider mini 750 light - and none of them fit. The company did provide good customer support and gave me a full refund. The only issue was with the hole covers. No need to buy other headphones by paying high fees These are pretty comfortable and block out all but the loudest noise. Had to return the book as was literally painful to read.