Allows the use of 13mm thick servos with David's brilliant tilt mechanism. I pulled my bits and bobs together for my V3 build and got the wrong servo. The casing is 13 mm thick instead of the nominal 11mm that the spacer fits. Rather than wait to find, purchase and ship the RIGHT servo, I whipped out a part in Tinkercad to fit the servo to the boom. I also had to file down the mounting tab lest it interfere with the boom. My servo was also longer than the designed spec. I included a 1mm spacer to go under the pivot mount. If that's not clear, you'll see it when you zip tie it all together. I'm gonna call this a derivative, cuz it weren't my idea, just my adaptation. Find a single part in an STL format, and a 4-up plate for high quality printing. I find that slowing down prints of small parts work well when I separate them in space and force the printer to slow down between each piece. I'm gonna add that I bought the kit from RCExplorer and I am boggled by the fantastic quality of his printed parts. He sets a very high bar.