New from the CNC wizards at Kartboy, this shift knob is designed exclusively for your six-speed Subaru tranny. It threads directly on, and has a nice contoured shape that fits nicely in hand. Each comes with both yellow and black Kartboy logos. (You can also get STi or replacement Kartboy logos, sold separately.)
1.90" ball diameter is not too small, not too big. 144 gram weight.