Monoprice Replacement Door Open Sensor Designed For the Monoprice Maker Ultimate 2 3D Printer 139172Technical assistance can be reached via live chat at Monoprice.com Monday through Friday 6am - 6pm PST, via email at [email protected], or via phone at 877-271-2592 Monday through Friday 6am - 5pm PST. Warranty: Replacing parts on your 3D printer may result in its warranty being voided. If you are having difficulty and are unsure if your printer is still under warranty or wish to prevent voiding your warrantytech@monoprice.com for assistance. Safety: Always exercise extreme caution when working $11.99Newegg.comDelivery: in USA ReportBuy!