I picked up a pistol-style shifter at Pepboys to try out with my extender and took some pictures. The extender is about 3 in long and most of it fit inside the shifter, leaving only about half an inch beyond the end.

Then you just screw it on the shift lever and tighten with a hex nut.
The result is not too bad - a long pistol grip shift lever that clears the reverse ring. I like how close it is to the steering wheel. The throw is not bad with my Cobb ss set to the shortest setting.