The throttle and display sets on the Apollo Light, City, Explore, Ghost, Pro, and Ultra are QS-S4 throttles! The QS-S4 throttle looks like this:
The QS-S4 throttle comes with a USB port in the rear for charging and firmware purposes. Our throttles are branded, but the part itself is not proprietary, and compatible display/throttle sets can be purchased from other sources under the name QS-S4. The throttle is available from us here: https://apolloscooters.co/products/lcd-display-throttle
The display manual for the QS-S4 throttle can be accessed in the attachments section of this article. If you have any questions about the throttle, please contact our team at firstname.lastname@example.org!