United Pixelworkers describes this shirt, writing:

Rdio has totally changed the way we listen to music here at United Pixelworkers HQ. Concentric rings—designed by Weightshift—on front, small Rdio wordmark on the left sleeve. Printed in white water-based ink on a Black Aqua American Apparel 50/50 poly-cotton blend tee.

Naz Hamid of Wieghtshift writes,

This month, we’re sort of back again on United Pixelworkers, courtesy of Rdio this time. The t-shirts that some of you were aping for in the Rdio branding work has only been made available thus far to Rdio employees. However, VP of Product at Rdio, Malthe Sigurdsson, gave the green light to get an Rdio shirt made for the masses. And so, working together, we picked this design out just for you. Go get one now.