An interbody spacer comprising a series of stacked walls connected by a common base, wherein the spacer collapses when pressed into an access delivery tube. During insertion, the walls can flex as a unit, like bending a deck of cards, to traverse bends in the access tube. Upon distally exiting the portal of the access delivery tube, the walls track apart (like spreading fingers) to create a wide base of support for the vertebral body endplate. A graft delivery device that uses a conveyor belt-type approach to deliver bone graft from the device to a location in a patient. In some embodiments, the conveyor-belt is manually actuated.