A push-in interbody spinal fusion implant having an expandable height. It is adapted to determine the lengths of the frames on a per link basis using one or more link parameters, the frame length hence being variable. The mobile device then identifies which of the cellular networks makes a data communication service available to it. When the composition is contacting the hydrocarbon-bearing clastic formation, the nonionic fluorinated polymeric surfactant has a cloud point that is above the temperature of the hydrocarbon-bearing clastic formation. The mask caps and residue polymer are easily removed after etching by washing the wafers in a wash of deionized water, or Buffered Oxide Etch. The self-closing device includes a plurality of retracting modules configured to retract the unit from a retracting start position towards a retracting end position.