These shift knobs were designed and manufactured by Harbor 2 Holdings for a friends RX7 ChampCar. After much convincing he decided to a limited production run of these. They won't be produced again so you'll have a unique, high quality, 1 of 15 shift knob. They have standard Mazda thread pitch of M10x1.25mm. They weigh 5.5oz and are anodized black. The may look crisp but they have been fully deburred and have no sharp edges. Our personal RX8 has over 300 miles with this shift knob and its perfect. It will get warm and cold sitting out in the weather, but because it's aluminum it returns to ambient temperatures rather quickly.