Here is the second piece in my order from the forwards thinking folks at Oscar Delta Special Projects Division.
The DCT (Deep Carry Tube) is an airtight and waterproof container, measuring 82mm (3.25") by 20mm (externally) and 16mm (5/8") internally. Both end caps are removable soft vinyl, smooth and extremely snug to the hard tube of the body.
The idea being that it offers a unobtrusive and subtle space to cache small sensitive or vital items.
My SERE v-cutter shipped inside it, and since getting it, I've carried it in the bottom of my front right pocket, it barely registers, and I have no doubt of its ability as a geocaching item, or means to secrete important or sensitive materials. As the folks at Oscar Delta SPD say, "Quite simply, an item that cannot be found, cannot be taken."