These are the full frames as listed on the stitch-along resources. They have webbing on the roller bars for whip stitching your linen on. Each one comes with the side bars as listed as four knobs so you can attach linen and lace it to the sides, having several frames up at the same time.
Silken Trinket Box Kit requires 1 - 18" roller bars with 6" sides.
Harmony with Nature Casket requires the 2 frame bundle:
14" roller bar with 12" sides and a 14" roller bar with 8" sides.