Description: Shock Absorption: This Bike Stem features an adjustable handlebar stem that provides near linear parallel movement relative to the ground, effectively reducing vibrations from uneven terrains. Product Dimensions: Height 4.5cm/1.77inch; Length 9cm/3.54inch; Handlebar Diameter 31.8mm; Front Fork Stem Diameter 28.6mm.Four Link Design: The unique four link design allows the handlebars to maintain a near float relative to the ground, enabling a more comfortable riding posture.Easy Installation and Use: This bike handlebar stem is easy to install and use, making it ideal for replacing mountain bike stems. It ensures safe riding with it up and down shock absorption feature that maintains your riding posture even during sudden brakes, providing a comfortable ride with 15-20mm of travel control.Adjustable Spring Hardness: Bicycle Shock Absorber Riser comes with four different spring of varying hardness levels, each color coded for easy identification. An 8MM hex wrench can be used for easy replacement.Aluminum Alloy Material: Made from high strength aluminum alloy, this product can maintain good usability over a long period of time. All four shaft rods are enhanced with DU copper sleeves for tight integration and smooth rotation. Specification: Material:Aluminum Alloy Size Chart: Length 9cm/3.54inch; Height4.5cm/1.77inch Package Includes: 1Bike Stem4 Spring Note: Please allow slightly errors 1-2cm differences due to manual measurement.