2021 Koling Thunderbird. Cheap price fast shipping in the US. Innova says this about the mold: “Big Jerm went radically retro with the Thunderbird this year. The Koling Thunderbird is just stiff enough for all the flicks while being soft enough to give you all the feel in the flight plate one would need to smash a backhand. As the Koling Thunderbird is known for, these have a bit more stability than your standard Thunderbird. The Thunderbird is predictable in wind and a great long range placement driver. Pros will appreciate the shot shaping ability of this driver while less experienced players will find a consistent, predictable flight.