USA seller, we are a small business based in Lancaster PA! Extension Damper, these are not shocks. These are used in drop down applicaions. Choose from 5N, 10N, 30N and 50N. The higher the N value, the more weight required to start the damper to extend. The more weight on the damper, the fast it extends. 8.58" extended length (from center mounted to center mounting), Extension dampers. Slowly allows the lid to lower on extension stroke only. No force required to close. Ideal for shelves or lids that lower / drop from the bottom. Package comes with damper, brackets and screws. No instructions. We are from Lancaster PA, we offer customer support, feel free to call us 845-402-6108. The rod end should always be the end pointing down when your shelf is open. THESE ARE NOT SHOCKS. THESE ARE USED IN DROP DOWN APPLICATIONS. 8.58" extended length, Extension damper. Slowly lowers lids on extension stroke only. No force required to close. Ideal for shelves or lids that lower / drop from the bottom. Comes with black brackets and screws. These have a QPQ black finish on the rod rather than the standard chromium finish others sell. This offers a much harder rod, much better rust protection, smoother movement and longer seal life! Keeps your shocks working at the lift rating much longer than others. If quality is important, this is your damper! These replace all brands. Features: Lids softly opens. Length (hole center to hole center) :8.58''; Travel:3.03'', black mounting brackets and Screws Included rod diameter: 6mm tube diameter: 15mm. The less weight, the slower it opens. The more weight, the faster no instructions Specifications: Color Black Type Gas Damper Quantity 1