Abstract: An apparatus is provided for use with a tissue anchor and an anchor driver. The apparatus includes a housing, shaped to define a channel. The channel includes (i) an anchor-storage zone, and (ii) a proximal opening configured to provide access for the anchor driver to the anchor-storage zone. The channel is configured to enable sliding of the tissue anchor therewithin to be stored in the anchor-storage zone. The apparatus also includes a retaining member, shaped to define a cradle for cradling and holding the tissue anchor in the anchor-storage zone. The retaining member includes a pillar pivotable with respect to the cradle, and configured to support the tissue anchor at the cradle. Other embodiments are also described.