The TP+ "whispers". The helical toothed TP+ is 6 dB(A) quieter than the classic spur toothed TP. These features are possible by incorporating the latest research in tooth geometry and dynamics. And we certainly don't have to spell out the added value you get from 64 decibels instead of 70. What's more, the TP+ reduces vibration to virtual imperceptibility for amazingly smooth running.