Thank you for viewing. I am selling these items as I am retiring from Mini 4WD. This is a set for barrel springs, using TOMOZONE's flex jig. ○ Horicomunder SP6.1 ○ Kezuricomunder 4.25 Although barrel springs themselves are difficult to obtain, I used them because I felt the flex performance was higher compared to AO springs. There is considerable wear and tear, but they can still be used without any problems. Please refrain from purchasing if you are sensitive to used items or are looking for something in new condition. Also, please purchase only if you can research how to use these items on your own. Mini 4WD Jig Flex Barrel Spring