These two feet allow you to mount a fender jazz bass pickup shield over your fender coronado bass ii reissue's bridge, mostly to give yourself some additional options for felt muting (i found squishing felt under the strings was a little too much muting for my purposes). the end result is basically like the bass mute i created for the jack casady bass (http://www.thingiverse.com/thing:36648), but more 'chromey'. here's some links for the shield: http://www.amazon.com/Fender-Accessories-001-0660-090-Chrome-Vintage/dp/B002HF483G/ref=sr_1_1?ie=UTF8&qid=1399305905&sr=8-1&keywords=jazz+bass+pickup+cover http://www.allparts.com/search.asp?keyword=jazz+bass+cover&sortby=0&catid=477 you will likely need to adjust the height of this (by dragging down or raising the bottom vertices, for example) to adjust for the height of your bridge - although these files work on mine, if you have a lower action, the adapter won't fit, and if you have a higher action, things could be a little floppy? if your shield is a little different from mine, you may need to work on the the width also. MAKE EXTRA SURE that the screws you use don't extend past the plastic and scratch your guitar's top. also, attach a liberal amount of padding (e.g., felt) underneath the plastic to keep your guitar's finish from getting marred. I used pickguard screws, which were too long, so I ended up using a stack of washers on each side to keep the screws in check. finally, as you can see the outer shape of the adapter has some crazy vertices - i got the shape from a scan of the shield and didn't bother to clean up the geometry, so if you're feeling ambitious, by all means take a whack at those too! oh PS you may want to add some tape on the underside of the shield to keep it from rattling against the bass guitar's bridge...! PPS it will save some frustrations by giving yourself a bit of room between the top of the bass and the bottom of the adapter, and then making up the space by stacking felt feet on the bottom - that will especially be the case if you are unsure whether you might want to back your action down in the future....! PPPS i added jbshield45 stl and thing files for a second shield/bass which required tweaked dimensions - the last photo is a picture of some stacked felt feet i used on the second bass...