constructed as disclosed in u s pat no 6 595 998 cited above the disclosure of this patent and most particularly its discussion of the construction of the wafers is incorporated herein by reference in the preferred embodiment the upper surface 58 defines a ridge 60 and spaced rib 61 extending along the longitudinal axis of the wafer similarly the lower surface defines a linear trough 62 that receives the ridge 60 and a notch 63 that receives the rib 61 the insertion configuration for the ibfd and wafer inserter apparatus is generally depicted in fig1 the wafer track 52 of the inserter apparatus engaged the ibfd with the track end 53 contacting the proximal faces of both the inferior endplate 14 and the superior endplate 12 a wafer 55 is shown resting on the wafer support surface 49 of the track connector 46 u2032 the track connector 46 rests on the support rail 40 see fig6 with its posts 47 projecting downward toward the post openings 44 in the inferior endplate 14 as shown in the figures the posts do not necessary extend into the openings 44 instead the post openings 44 facilitate the assembly of insertion apparatus to the track connector prior to use beneath the track connector 46 reside an insertion.