This guard protects your gimbal from damaging when touching obstacles. PLA with carbon reinforcement. PLA is better for this. Do not recommend 100% infill. 20-30% is enough. Carbon makes this part MUCH stronger. Definitely needed. Tracker mounted with double sided adhesive tape and fixed with small zip tie. You can use it without tracker - no problem. This version is very good, so I would not modify in the near future. Print, mount and fly. And yes, yellow strip at the picture - this is velcro, that I use to prevent stock gimbal holder from taking apart.Print with PLA, 25% infill Add carbon insert (~1mm thick, ~5mm width ~150mm long) Carbon can be fixed with zip ties (take a look at the pictures)