About this 3D model

Doorknob extender for arthritic people. Uses grooves on the side to tightly hold to round doorknobs and extends into a lever. This cost around $2.50 to print while commercial products on amazon were $10 / handle https://www.amazon.com/Ableware-Doorknob-Handle-Extender-754161002/dp/B000PGRKZW/ref=sr_1_1?ie=UTF8&qid=1540480315&sr=8-1&keywords=door+knob+extender. This design does not require any extra items to secure together, utilizing grooves and tabs.