The Gemma Freecoaster is designed by a Korean BMX shop owner named Lee, he designed the hub to be a mix of a Nankai and a Geisha. They are produced by an OEM parts manufacturer called ART. They are supposed to be pretty reliable. It is sealed, 10t, has a 14m axle, a 36h hub shell, and weighs 20.7 ounces. The axle is broached to accept a 6 mm allan wrench. That is as much as I can decipher from the bad translation available from Korean.