When I got my Givi Outback Trekker top box I was intrigued by how similar the key is to my 2011 GSA. I got the Trekker top box because I like the mount system that Altrider offers for the cargo platform I have; I can mount the box all the way aft or the passenger seat location. I have the BMW panniers and would like to have just one key. After removing the lock from the Trekker and recalling what the BMW locks look like I figured the Givi lock could be modified to use the BMW key. It can be; and here is how to do it. First, I ordered a lock set from Revzilla, I did not want to be without the lock on my case in case it did not work. The Givi part number is SL101, it is $19. Here is a comparison of the two locks and keys. Givi on top and BMW bottom. The BMW key is about 0.025" wider and just a bit shorter. The first thing to do is remove all of the tumblers and the tiny springs that go with them. They can be pulled out from their wide side with small pliers or pushed out from the narrow side. Notice that the first plate at the front is not a tumbler held in with a spring. It is a shield that allows only the right key type to enter. It is a little too narrow for the BMW key. Use a square jewelers file to make the shield plate a bit wider to fit the BMW key. The next step is to file the lock assembly a little wider so that the BMW key will fit. There is a spring loaded trap door at the front of the lock and I wanted to keep it out of the way of the square jewelers file so that it did not get filed along with the lock internals. In the end I put some masking tape on the two faces of the file that were orthogonal to the surfaces that need filing and this kept the trap door from getting filed. Each of the ribs that you see must be filed a bit to allow the BMW key to fit. There are ribs on both sides that must be filed. The metal is soft and files easily. After filing there may be some small burrs at the edges of the ribs that should be removed with an X-Acto blade. Here is the lock after widening for the BMW key. Finally, blow, or rinse out, any filings in the lock body. The next step is to find the correct order of the tumblers to allow the lock to operate. This type of lock pulls the tumblers in to be flush with the lock body to turn the key. There is probably a method to figure out what tumbler to use where, I used trial and error. Here is the lock with the first three tumblers fit. Notice the shield at the top of the photo. As you fit each tumbler you must test to see that the lock will turn before moving to the next. Notice that some tumblers have the inside tab on the same side as the outside tab that rides on the spring; others have the inside tab on the opposite side. I was able to find a tumbler that fit for 7 of the 9 positions after some trial and error. The last two tumblers turned with a little drag and I noticed that with the key inserted there was movement of the tumbler only in one direction, the others had a little free play in both directions. I used the file open the bottom of the tumbler on one and reduce the tang on the other and they turned freely. The end result is that all of the tumblers could be used. If not all of the tumblers could be made to work it should be no problem to leave a few out. Be careful with the tiny springs. If you lose any they are the same as the BMW lock and your dealer probably has about a million of them from all of the lock sets keyed over the years, mine does. Unfortunately, the BMW tumblers are thicker than the Givi tumblers so they cannot be used, unless one has the patience to thin them. There are only 3 different tumblers for the BMW lock but the Givi lock seems to have 6 different tumblers. After fitting all of the tumblers I shot some spray white lithium grease in the whole thing and exercised the lock a bit. I installed the modified lock in the top box and it works perfectly. It is really nice to have a common key for everything on the bike.