We can legally sell, and you can legally purchase and own, this kit because the kit does not contain a fully-functional and completed TCGTR, but only provides the materials necessary for creating one -- meaning the kit cannot be used to convert an AR-15 to full-auto, as-sold, but would have to be modified, by bending the provided TCGTR material into the correct shape necessary to create a fully-functional and completed TCGTR. (Be forewarned that if you chose to do this, you would have created a new part from the materials provided to you in the kit, and this new part would be one of your own making. In other words, you would be its manufacturer.)