Here is a look at what came in the box:
To describe the 4 inserts provided, in terms of the length of the part of the insert that is internal to the muffler: there are 2 long and 2 short inserts.
The longer ones are more restrictive hence quieter than the shorter ones. For each pair by length (e.g. the long pair), there is a "skinny" smaller diameter one (with no tube sticking out the back) and a "fat" larger diameter one (WITH the tube sticking out the back). The skinny one is more restrictive hence quieter than a fat one of the same length.
In addition I think the spark arrestor (SA) will not fit on the "fat" ones since they have the tube sticking out the back.
So you have these 4, and this is my guess at listing them in order from LESS Restrictive ("loudest, highest performance") to MORE Restrictive ("quietest, lowest performance"):
Here is a comparison of the relative sizes of the Leo vs. the OEM muffler:
One of the issues with the BMW exhaust in general is that the exhaust header pipe has VERY LITTLE clearance from the coolant hose and some people have had their hose seared by the pipe:
To help improve this clearance, after you remove the OEM muffler you can then loosen the 2 exhaust nuts at the head and rotate the header pipe to gain a bit of clearance, then retorque them.
Here are some before and after pictures of the clearance to the water hose, and of the overall look:
A fix for a potentially SERIOUS problem: Because of how the LV muffler is bolted onto the frame, it is only bolted in one place with a bolt mechanism that can rotate to fit into any position.
The problem is, even if you apply blue threadlocker, riding off road can eventually cause this adjustable junction to rotate and let the muffler sag, in which case the exhaust header pipe can come close to searing the coolant hose.
My solution for this was to take a thick aluminum strap and bend it to fit around the rear tail rack bar (in my case, or a grab rail bar on a stock bike).
Then I drilled a hole into it and slipped the exhaust bolt through it. This adds plenty of support.
Also notice the use of a spacer to move the exhaust out a bit farther (to provide clearance away from the Wilbers shock reservoir I added later).
Finally, the small front heat shield was a bit of an annoyance as it stuck out so far it rubbed against your left calf, especially with full riding boots on.
In addition, the heads of the screws that hold the heat shield on were digging into my leg.
My fix was to bend the brackets in a bit, and to use stainless flat head screws instead, which have a lower profile. Plus to minimize the heat further I put some hi-temp black silicone RTV (Permatex Ultra Black) over the heads of the screws (which helps mainly when riding in shorts :). I also installed exhaust heat wrap on the pipe (partly to lessen the heat on the Wilbers shock reservoir too).