Piaggio Front Shock Absorber for Vespa LX, LXV, and S Models. This shock will fit on the ET2 and ET4, but it is not the correct shock for those scooters. That part is 598922. 

Piaggio Part Numbers  601997, 56214R, 56266R, 58509R, 646959. 

Vespa LX 50 (2006-2009) - 4-Stroke 2-Valve Vespa LX 50 (2010-2014) - 4-Stroke 4-Valve Vespa LX 150 (2006-2009) - Leader Motor (2-Valve) Vespa LX 150 (2010-2014) - Fuel Injected Leader Motor (2-Valve) Vespa LXV (2007-2009) - Leader Motor (2-Valve) Vespa LXV (2010-2016) - Fuel Injected Leader Motor (2-Valve) Vespa S 50 (2009-2014) - 4-Stroke 4-Valve Vespa S 150 (2008-2009) - Leader Motor (2-Valve) Vespa S 150ie (2010-2014) - Fuel Injected Leader Motor (2-Valve)