Unfortunately I recently dropped and broke my scales so I can't get a measurement at the moment. I'm going to try and borrow some soon. They can't weigh more than a few grams though.

Here's a video of the prototypes being demoed in some of Alex's robots:



Due to RS being out of stock on the motor driver chips I use for the High Voltage boards, I unfortunately won't be able to make any more of those until after the 11th of July.