If you own an HPI E-Savage RC truck, this FastEddy bearing kit is exactly what you need to keep it running smoothly! The kit includes all the essential bearing sizes you'll need: (4) 5x11x4mm, (4) 6x10x3mm, (10) 6x12x4mm, and (8) 10x15x4mm bearings. These sealed bearings are so much better than the stock bushings - they reduce friction dramatically, which means more speed, longer run times, and less wear on your drivetrain. The quality is excellent - FastEddy is known in the RC community for producing reliable bearings that hold up to the abuse these trucks can take. Installation is straightforward if you're comfortable with basic RC maintenance, and the performance improvement is immediately noticeable. Your E-Savage will run quieter, cooler, and more efficiently. Just a quick tip - double-check your specific model and any hop-ups you've installed, as bearing sizes can sometimes vary between production runs. I replaced the stock bushings in my E-Savage with this kit, and it was like getting a whole new truck! The wheels spin freely, the transmission runs smoother, and I'm getting noticeably better battery life. If you want to upgrade your E-Savage's performance and reliability, this bearing kit is one of the best investments you can make for your RC vehicle.