Insert Straps

Start by inserting strap-a.stl into one of the slots on the bumper. Pull it all the way through until the extension gets caught. 

Insert strap-b.stl by pushing the extension stopper through the second slot. Pull the stopper through the slot.

Fasten Straps

Use the holes on strap-a.stl to adjust the size. The nub on strap-b.stl can be pressed through one of the holes. The excess from strap-a.stl can be inserted into the slot on strap-b.stl

Install Circuit Playground onto Bumper

Line up the JST and microUSB ports on the bumper so they're in line with the cutouts. The PCB from Circuit Playground is fitted into the bumper with the edges tucked into the lip. Press the PCB into the bumper so the edges are all tucked in.

Bumper and Strap

The back of the bumper has an opening, reveling the lovely silk screen on the back of Circuit Playground.

Fitting On Wrist

While fitting the strap onto your wrist, you may find one of the extension stoppers will come loose and pull through the slots on the bumper.

If that happens, you might fine it easier if you buckle the two straps together first, and then pull one of the extension stopper through the slot.

Then, install Circuit Playground onto the bumper while the fitted is secured to your wrist.

Plug In Battery

A lipoly battery can be tucked underneath the PCB or band. Try both ways and see which is more comfortable and practicle.