A compact version of Tama's Rhythm Watch, the RW30 Rhythm Watch Mini is a metronome specifically tailored for drummers. For instance, its built-in clip allows you to attach it to various surfaces, such as your hi-hat stand. Running on two AAA batteries and measuring 2.4 x 1 x 4.7", the unit is quite portable. It provides a tempo range of 30 to 250 BPM and allows you to practice in odd as well as even time signatures by dividing the measure into anything from 1 to 9 beats.