O ring kits / O ring Boxes are used for effective sealing of hydraulics and pneumatic machines. Offered boxes or kits contain multiple NBR O rings that are well known for their excellent sealing attributes. NBR products can resist damaging effects of silicon grease, petroleum oil, hydraulic fluid and water. Chemical properties of these NBR products can be modified by blending PVC or by conducting hydrogenation process during their manufacturing. High elasticity level, excellent mechanical attributes, wear proof design and wide temperature range are the key aspects of these NBR products.