This includes the right BB size, clip type, proper rail mounts for scopes, battery sizes, etc. Its normal on RC sailboats for a winch servo to supply for the control of the sails, compared to a standard servo. http://Tour.Temnikova.ru/bitrix/redirect.php?goto=https://www.storyspritz.com/2024/09/06/science-fair-projects-you-dont-have-to-be-happy-ho-hum/