DCT: DEEP CARRY TUBE The DCT (Deep Carry Tube) is a compact and light weight concealment device ideal for documents, geocache, emergency cash, glow sticks, matches, sewing kit, fire lighting kits, spare batteries (CR123A, AAA, AA) and other small items The design has remained unchanged since 2006: Length without end caps 82.5mm (3.25 inches) External Diameter 20mm Internal Diameter 17mm (5/8 inch) Simple Design Lightweight Airtight Waterproof/Mildew-Proof Silent Operation 100% non-metallic Vinyl End Caps for comfort when worn against the skin.