This kit has a built-in speaker and a LED that indicates the beat. The volume and beats per minute can be adjusted with the potentiometers. There's also an on/off switch on board.
Specifications:

1. power supply: 9V battery (not incl.)
2. dimensions: 60 x 43mm / 2.4 x 1.7"

manual_mk106.pdf

module_diy_kit_guide.pdf