opened without wireline while providing a landing for a wireline plug which may be required for vertical well sections during related operations application_number US 201113336661 A description generally the present invention provides a subassembly 1 with at least two pressure sealing mechanisms comprising i a burst disc 4 and ii a fitting 2 for a profile plug 5 the fitting comprising a recess the burst disc 4 is generally deployed below the profile plug fitting 2 when the subassembly 1 is used and the inner passage of the subassembly 1 when sealed by either an intact burst disc 4 or a plug 5 in the profile plug fitting 2 or both does not permit fluid flow from tubing attached below the subassembly 1 through the subassembly 1 to tubing or the wellbore above the subassembly or packing between the wellbore and the tubing wherever located the burst disc 4 most typically made of breakable ceramic or similar substance is designed to be breakable broken by exertion of force from above the disc 4 such as by increasing fluid pressure within the conduit of attached wellbore tubing above the subassembly 1 while remaining unbroken unbreakable by pressure exerted on the burst disc 4 from below the disk thus the tubing string into which the subassembly 1 is assembled not shown but connected to the tubing string of the well at the upper end a and at the lower end b above and below the subassembly 1 respectfully can be.