The guee aero x smart rear light is an eye catching light that will warn any other road user of your road position this smart tail light comes with brake sensor technology which increases the flash rate and brightness when you are slowing down in turn making you more visible and pronounced to the vehicle behind you designed with an adjustable wing the aero x can be mounted on both aero and round seatposts meaning you are able to swap between bikes in a matter of seconds make sure you have