Do you need to hide micro film from prying eyes? What about coded messages? Are you secretly a member of the Cold War era KGB in need of a more secure dead drop? Of course you’re not, but that doesn’t mean the idea of a hollow bolt for secure storage can’t be repurposed for modern use. That’s exactly what’s been done with this 3/4″ diameter bolt. Unscrew the reverse threaded bolt head and you have access to the O-ring sealed (so yeah, it’s waterproof) secret storage compartment that measures .49″ in diameter and 2.81″ deep. That doesn’t sound like a whole lot of room, but it’s enough space to fit rolled up cash, a small handful of precious gems or similarly sized items or a Micro SD card. If you’re looking for a place for your secret Vegas stash or 128GB of data on a Micro SD (That’s a lot of state secrets!), this is it.