Imogen says she prefers the larger button which has a housing of about 11.5 x 11.5 x 3.5 mm and the button itself only barely protrudes from the casing and is a circular button of about 6.5mm diameter.
lowest left button in this image >> https://farm4.staticflickr.com/3926/14605978635_06f8417a5b.jpg
here it is with leads in shrink tube (red) >> https://www.flickr.com/photos/plusea/14503252529/in/set-72157645169552739
Hardware Assemblies >> http://mimugloves.com/dev-blog/hardware-assembiles/
Connection to carrier board: DO NOT DO THIS!!! x-BIMU is connected to pin 1!
Pushbutton added to x-OSC input pin 1. 10K pull-up resistor to 3.3V
Screen-shot of button presses and affected sensor values:
Right hand button ring. The ring is so tight that it is affecting the sensor input of sensor #7, the top knuckle of the index finger.
Left hand button ring. The ring is not as tight and has no visible affect on sensor input.