Prodigy Discs says this about the A4: The all new A4 is the latest in our range of approach discs. The A4 is a slightly over stable disc that fills the distance gap between midranges and putters and is designed for all skill levels. The disc is consistent and reliable in moderate wind conditions and perfect for short approach shots. It works equally as well for backhand or sidearm throwers. The A4, like the A3 has a bead on the rim. You can expect it to fly slightly less stable than the A3 with an extra 40-50 feet in distance.
About 350 RX Series Plastic
350 RX: The 350 RX is an exceptional plastic that feels great. It has just the right amount of stiffness needed for a high quality lightweight disc and enough toughness to break it in over time.