I have this knob on both my dueces. I also have not weighed them, dont have a small scale, food scale, or scientific scale. It does seem a bit light to my preference. The ball shape is not optimal for me. I tried out this Momo cylindrical one with slight angled bottom and top, felt amazing!I have on but unfortunately I don't have a scale to check it, I know its very light though, I didn't like it personally because I just have a preference towards metal but its in great shape - pm me if interested.
*edit* did some searching and found a weight of 4oz quoted here
This is the very same one I have- it's a carbon fiber (look) midsection and chrome on the top and bottom. It's well weighted and I've had it since I got my Spyder back in 2004 (came with the car from the Toyota dealership):I have an OBX cylinder knob As I recall 36g not heavy but it's height gives you move leverage + it has that awesome carbon fiber: 25 shipped if in continental US (fits spyder threads came with the car)