Signswise 3 Pack Mechanical Endstop for 3D Printer Makerbot Prusa Mendel RepRap CNC Arduino Mega 2560 1280 Easy to install, items are commonly used System normally need at least three pieces of mechanical switch Mechanical Endstop perfect for any 3D printer (Including Prusa Mendel i2, Prusa i3, MendelMax, Rostock etc...) also for use on CNC machines and other electronic applications. 3 Packs