mamaRoo Vertical Reciprocating Assembly Including: Full Reciprocating Motion Mechanism and Drive Slide & Lift Assemblies Nylon Vertical Gear Link Yokes Gears Components Crankshaft Compression Coil Springs DC Motors and Wiring Belt, Pulley, Encoder Wheel Gear Drive Linkage Arms Movement Arms & Components Double Scissor Lift Mechanism Nylon Bushings, Metal Washers, and Hardware Rigid Bottom Platform Supporting Top Platform Optical Photo Sensor Fits Following Models: Mamaroo 2.0 (4M-005) manufactured 2012-2015 Mamaroo 3.0 (1026) manufactured 2015-2017 Mamaroo 4.0 (1037) manufactured 2017-2022 Mamaroo 5.0 (1046) manufactured 2022-present