This is an alternate nubby cover design for extra traction in water. (Note: I did NOT copy from the sphere waterball housing or sphero paddles. I had this almost entirely though out before i even saw them) I am working on an alternate model for use with 3D printer material. the final product can be made out of silicone like the original nubby cover. @orbotix / @gosphero I don't know what license to use for this design so i have "creative commons-attribution-noderivitives" checked, as well as "All rights reserved." I will try getting the latest version printed and put up a video comparing the normal sphero 2.0, the sphero 2.0 with a turbo cover, the sphero 2.0 with a nubby cover, and the sphero 2.0 with my own nubby h2.o! thanks for downloading!The first picture is my latest design. just print two, get two rubber bands, and ta-da! None of these have been tested, except for a version of the latest file that was 3mm too small. :)