A really compact and multipurpose bit of kit, great for a variety of projects. I have several of these, the latest I bought for use with BeebSCSI to emulate a HDD on my Acorn Electron and BBC B micros. When plugged into a 1MHz level shifter via the header this works perfectly and brings hard drive functionality to these old machines with a minimum of effort. They can also be used in a similar way via a Tube adapter to provide co processors to these machines enhancing them even further. Very happy with this and will be purchasing another very soon from The Pi Hut who supplied it at a great price and delivered it within a couple of days. Excellecnt product, excellent service.