A liner hanger is used to hang-off and seal casing into a previously installed casing string in the well bore, and can provide a means of tying back the liner for production to surface. Dril-Quip has developed a state-of-the- art liner hanger system and has installed its liner hangers in a number of difficult well applications, resulting in improved industry recognition and market opportunities. A subsea control system provides control of subsea trees, manifolds and other ocean floor process equipment. Dril-Quip has developed a variety of subsea control systems, including fiber optic based multiplex control systems that provide real time access to tree functions and tree equipment status. The control system can be packaged for shallow water or deepwater applications. Dril-Quip also manufactures control systems used in the installation, retrieval and workover of production equipment. A subsea manifold is a structure located on the ocean floor consisting of valves, chokes, flowline connections and a control module used to collect and control the flow of oil and gas from subsea wells for delivery to a terminal. Surface Equipment . Surface equipment is principally used for flow control on offshore production platforms, TLPs and Spars. Included in the Company’s surface equipment product line are platform wellheads, platform production trees and riser tensioners. Dril-Quip’s development of platform wellheads and platform production trees was facilitated by adaptation of its existing subsea wellhead and tree technology to surface wellheads and trees. Platform wellheads are pressure-containing forged and machined metal housings in which casing hangers are landed and sealed at the platform deck to suspend casings. The Company emphasizes the use of metal-to- metal sealing wellhead systems with operational time-saving features which can be used in high pressure, high temperature and corrosive drilling and production applications. After installation of a wellhead, a platform production tree , consisting of gate valves, a wellhead connector, controls, tree cap and associated equipment, is installed on the wellhead to control and regulate oil or gas production. Platform production trees are similar to subsea production trees but utilize less complex equipment and more manual, rather than hydraulically activated, valves and connectors. Platform wellheads and platform production trees and associated equipment are designed and manufactured in accordance with customer specifications. Riser tensioners are used on a floating drilling/production vessel to provide a continuous and reliable upward force on a riser, independent of the movement of the floating vessel. Offshore Rig Equipment . Offshore rig equipment includes drilling riser systems, wellhead connectors and diverters. The drilling riser system consists of (i) lengths of riser pipe and associated riser connectors that secure one to another; (ii) the telescopic joint, which connects the entire drilling riser system to the diverter at the rig and provides a means to compensate for vertical motion of the rig relative to the ocean floor; and (iii) the wellhead connector, which provides a means for remote connection and disconnection of the drilling riser system to and from the blowout preventer stack. The wellhead connector provides remote connection/disconnection of the blowout preventer stack, production tree or production riser to/from the wellhead. Diverters are used to provide protection from shallow gas blowouts and to divert gases off of the rig during the drilling operation. Wellhead connectors and drilling riser systems are also used on both TLPs and Spars, which are being installed more frequently in deepwater applications. The principal markets for offshore rig equipment are new rigs, rig upgrades, TLPs and Spars. Drilling risers, wellhead connectors and diverters are generally designed and manufactured to customer specifications. Certain products of the Company are used in potentially hazardous drilling, completion and production applications that can cause personal injury, product liability and environmental claims. See “Item 1A. Risk Factors— 8