This Thing is a extension for a microSD card. It is meant to make it easier to get the card into and out of a tight space, like the printrboard of a Printrbot 1405 (the one I designed it for). I got the idea from the L shaped sd holder for Printrbots I saw out there already, but I needed it to be straight for my printer.
V1 is just a handle that can only be removed from the SD card by sliding the card in and out from the side. For the Printrbot Maker 1405 that means during operation the handle can not be removed. (you could slice off the end stop and print just 1/2 of the holder so it could slide off or...)
I have broken two sd cards by accidentally leaving the card plugged in with V1 and messing about with my printer. If you go with V1 just be careful not to do anything but pull it in and out.