Flowmass is slightly tapered with more material on one end - make sure the heavier end is installed at the far end of your prop, where it counts.

Installing/removing flowmass onto crystal cases:

There is a circular symbol on the flowmass that aligns with the button facet on the crystal case, which also aligns with the flowlight button. You MUST align the symbol on the flowmass with the button facet on the crystal case before installing the mass otherwise you might rip the crystal case. This alignment also allows you to feel for the button from the outside, and creates the most aesthetically perfect positioning of the mass with respect to the crystal case.

Thread the leash through the mass and use the leash to pull the crystal case into the mass. You can hold the leash with one hand and pull the mass along the length of the case with your other hand until the mass is where you want it. If this is difficult, try hooking your handles or leash onto a doorknob or other secure object to pull on it.

Removing flowmass from crystal case: 

You can remove flowmass by holding the mass in one hand and pulling on the leash with the other.

You can find flowmass on our website here: http://www.flowtoys.com/flowmass-pair/

If you have any questions, please feel free to contact us!