The Telescoping Seat Post is equipped with a quick-release expansion mechanism, providing a more customizable and comfortable fit for both shorter and taller riders. Retracts to make folded eBikes even more compact. Compatible with 43.9mm seat tubes. Compatibility: Lectric XP (XP 1.0, XP 2.0, XP 3.0, & XP4 Models) Lectric XP Step-Thru (XP 1.0, XP 2.0, XP 3.0, & XP4 Models) Lectric XP Lite (1.0 & 2.0 Models) Lectric XP Trike (Model 1 & 2) Lectric XPedition (1.0 & 2.0 Models) Lectric XPeak Lectric XPress Lectric ONE Notice: Depending on the model of bike you have, you may need to remove or add a Seat Post Shim to properly install the Telescoping Seat Post. Product specifications: 550mm total extension from minimum insert Dual Seat Post outer diameter: 34.9mm Material: Aluminum