I designed, ordered, and received these recently. The protoboard spacing is a standard 0.1″ grid, plated-through holes. The slits on either side of the prototyping surface are designed to fit a 20mm-wide “NATO” watch band, allowing convenient and easy wearable electronics.

I have a few different ideas for these, such as:
– digital clocks/timers (numeric and binary)
– personal atmospheric monitors (temperature, humidity, barometric pressure)
– location trackers, navigation tools (GPS)
– personal health monitors (body temperature, heart rate, perspiration rate)

Look for these protoboards to be on sale at tindie.com soon.