This is the ProTek RC Universal Radio Case Insert, intended for use with the ProTek RC Universal Radio Case and Sanwa M17 Transmitter. This high density foam insert will allow you to adapt the Universal Radio Case to fit the Sanwa M17 Transmitter, keeping your valuable equipment safely cushioned within the case. But, this insert features more than just a cut out for your transmitter! Additional pockets have been added so you can keep spare servos, receivers and other accessories tucked away safe and secure, within easy reach when you need them.