I got mine 2nd hand for AUD$100 ($US75) 22" wide (straight across excluding the curve) and 20" tall (measured in the center of the shield from the dip between the headlights to the top of the shield).
As stated above it fits to the same fork mounts as required for the black Flyscreen or clear Sportscreen. The previous owner had also added some additional customised brackets to allow further angle adjustment. I found the buffeting noticeable at first with my beard whipping my cheeks confirming
@TO rocket 's comment that it comes from below.
I have since fitted custom stainless steel lowers I bought from the UK on eBay (see Post#3 here
Lower Deflectors for the Rocket ).
That thread will assist you a lot.
I had to make up some brackets to mount them to my existing screen brackets and then relocate my stock front blinkers to the new SS lowers. There is a good 10" of cable each side available to do so and I did not have to cut or re-wire anything. I mounted mine much higher than
@1K9 did in Post#1so they are behind and overlap the bottom of the screen. Hence the need to relocate blinkers.
It seems to have worked well but I have not experimented with screen angle heights or angles yet.
Before I cut a vent hole in the screen I will experiment with the gap between bottom of screen and twin headlights and the screen angles. I look over the screen, not through it and prefer that I think.
I have thought about copying the adjustable and open/closing Clearview venting system by finding and using a car dash vent from an auto wreckers, cutting the hole to suit with a Dremel rotary tool.