These levers are a replacement for the external cable actuation on a Thomson dropper seat post with external routing.
Each lever is machined out of aluminum in California, then black anodize to match the Thomson anodize.
Disclaimer - the lever is designed as a concept and is not advised to make on the fly adjustments as removing your hands from the bars because it is dangerous, this is for quick adjustments when not riding, I take no responsibilities for how you use it.
Depending on your seatpost age and inner workings, seat position and rail location it may slightly hit the rails, it will still lower and work but because of so many variations in rails and posts it should be noted.