One aspect of the present invention relates to a retaining element for securing at least one elongate member to an installation surface in conjunction with a fastener. The retaining element includes a first portion and at least one second portion. The first portion secures the retaining element to the installation surface. The at least one second portion engages the elongate member. Also, the second portion defines a single continuous arch formed by a plurality of engagement surfaces disposed on a bottom side of the second portion. The engagement surfaces define a portion of the perimeter of at least two substantially overlapping shapes, such as ellipses, having different dimensions. In this way, upon installation the elongate member directly engages and is secured to both the installation surface and at least one of the engagement surfaces.