The P-R & P-RN Profile Landing Nipples are made up to the tubing string for a compatible Lock Mandrel to engage, seal and lock inside the internal profile to provide a setting point for flow-control equipment such as valves, chokes and plugs. The ‘P-RN’ Landing Nipples are considered ‘Non-Selective’ Locking Profiles and are typically run in single nipple tubing strings, or as the bottom nipple in a series of ‘Selective’ ‘P-R’ Nipples. This is due to the incorporation of a No-Go for the purpose of location. The No-Go can be found below the seal bore of the nipple if it is a bottom no-go nipple or at the top if it is a top-no-go nipple. An operator can place as many ‘Selective’ nipples with the same ID in the tubing string (without regard to a specific sequence) to provide more positions for setting and locking subsurface flow controls. P-R & P-RN series Nipples are used in heavy weight tubing strings.