TSK CSH (Closed-Tip Single Side Hole) Cannulae 25G x 50mm (2") Uses: Ultra thin wall 35% less extrusion force needed Reduced risk of trauma Smoother & more controlled injection The CSH sets itself apart from other cannulas in the market because of the ULTRA thin wall. A larger internal diameter results in up to 35% less extrusion force and therefore a smoother and more controlled injection.