I'm an engineer that specializes in reverse engineering and haptics, known for my sex tech work. For each ko-fi ($3), if you include your address (AS A PRIVATE MESSAGE) I'll also send you the sticker of your choice! Choose between Nonpolynomial, buttplug.io, and buttplug-rs! (For multiple stickers, donate multiple Ko-fis and specify what you'd like!) Note: Buttplugs do not actually cost $3, but it's wishful thinking.