This is a tip mod to adapt to a 1 inch wide sanding stick, it will put a small curve so you can sand on the inside of a radius without gouging your parts. The Orange stick is the new stick I bought from amazon, the Red stick is almost 30 years old from my college days. https://www.amazon.com/gp/product/B000BRUDZ4/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1