31.6 mm Mountain Bike Seatpost Road Bicycle Dropper Hydraulic Lifting Remote Control Adjustable Seatpost Tube ( Item#: Y19459-3 )

The comfortable oil pressure suspension has a pain-relieving effect on the back area as it provides optimal shock absorption and makes soft reaction during cycling. 

Features:
The height can be adjusted freely between 0~100mm.
The hydraulic system can provide sufficient pressure , achieve better riding experience.
Suspension seat post with coil spring improves both the riding comfort and the buffer ability. 
Extreme torsion (10.9 N ) being applied to the screws, offers superior stability.
Clamp head angle is adjustable, you can find a comfort saddle angle for your personal love.
Seal ring isolates it from dust, water and prevents  oil leakage efficiently.
Quality Aluminum alloy construction,strong, durable and corrosion-resistant.

Specifications:
Material: Aluminum alloy.
Color: Black.
Angle: -5° + 18°
Ttravel: 100 mm / 3.9 in
Type: External Cable Routing / Internel Cable Routing ( optional ).

Internal Cable Routing:
Diameter: 30.9 mm / 31.6 mm (optional).
Seat Tube Length: 400 mm / 15.7 in
Inner Cable Length: 170 mm / 6.7 in
Weight: 653 - 679 g / 23.0 - 24.0 oz

External Cable Routing:
Diameter: 30.9 mm / 31.6 mm (optional).
Seat Tube Length: 375 mm / 14.8 in
Weight: 628 - 650 g / 22.2 - 22.9 oz

Product Weight: 1746 g / 3.8 lb
Packing Size: 45 * 5 * 5 cm / 15.7 * 2.0 * 2.0 in
Packing Weight: 700 g / 24.7 oz

Package List: 
1 * Bike Seatpost