A fastening clip for attachment to a threaded elongate fastener , comprising: a base plate , having a proximal face and a distal face, comprising a central through hole defining a centre axis and forming a frustoconical sleeve extending away from said proximal face along said centre axis and which is configured to guidingly receive the threaded elongate fastener ; at least two diametrically opposing resilient retention arms, each one extending from a peripheral edge of said base plate radially outward and invertingly folding back towards said centre axis , so as to provide two cooperating end portions operable to resiliently move substantially parallel to said centre axis between an unbiased position, where said end portions are positioned proximally spaced apart from said frustoconical sleeve, and wherein said resilient retention arms have a space between said two cooperating end portions defining an axial freedom of movement of said resilient retentions arms, and a biased position, where the end portions are configured to retainingly and biasingly engage with a threaded elongate fastener when inserted through said central through hole, and wherein each one of said two cooperating end portions further comprises at least one recessed portion adapted to receivingly and attachingly engage with a corresponding installation tool , characterised in that one of said two cooperating end portions comprises at least one ramp member extending from a distal end in a direction nonparallel to a central longitudinal axis of said end portion of said retention arms so as to slidingly engage with a distal end of the other one of said two cooperating end portions during movement between said unbiased position and said biased position. a base plate , having a proximal face and a distal face, comprising a central through hole defining a centre axis and forming a frustoconical sleeve extending away from said proximal face along said centre axis and which is configured to guidingly receive the threaded elongate fastener ; at least two diametrically opposing resilient retention arms, each one extending from a peripheral edge of said base plate radially outward and invertingly folding back towards said centre axis , so as to provide two cooperating end portions operable to resiliently move substantially parallel to said centre axis between an unbiased position, where said end portions are positioned proximally spaced apart from said frustoconical sleeve, and wherein said resilient retention arms have a space between said two cooperating end portions defining an axial freedom of movement of said resilient retentions arms, and a biased position, where the end portions are configured to retainingly and biasingly engage with a threaded elongate fastener when inserted through said central through hole, and wherein each one of said two cooperating end portions further comprises at least one recessed portion adapted to receivingly and attachingly engage with a corresponding installation tool , characterised in that one of said two cooperating end portions comprises at least one ramp member extending from a distal end in a direction nonparallel to a central longitudinal axis of said end portion of said retention arms so as to slidingly engage with a distal end of the other one of said two cooperating end portions during movement between said unbiased position and said biased position. <EOS>