Thank you for viewing. This is a set sale of the rave d servo RS-ST and the gyro Revox. Please note that we do not sell these items separately. Each product has been tested and confirmed to be working. There are no gear chips or other defects in the servo. However, since these are used items, please understand that we do not accept returns or claims after purchase. Please refrain from purchasing if you are overly concerned about the condition. * The servo data has not been initialized. Please initialize it before use. We do not have a program card, so we cannot initialize it. Instant purchase is welcome. Thank you.