The first two at the top of the unit are specifically for your Apple devices such as iPad, iPhone or iPod, as they feature self-sensing technology which means they automatically detect which device is attached and change the charging parameters accordingly. The third and fourth USB ports have been designed primarily with Samsung and Nokia devices respectively in mind but will support any device that can be charged via 5V USB. The spidermonkey has three input options; via 5V AC transformer socket, micro USB socket, or 5V-30V socket. Ready to use straight out of the box, we have included a universal AC charger, you can also power the spidermonkey via our gorilla range of chargers through the 5V-30V socket or via the powermonkey extreme through the 5V AC socket. Charging via the powergorilla allows you to use the gorilla's multi-voltage settings to increase the power to the USB sockets dependent on your needs. The spidermonkey can also be powered from your computer's USB port, making it the perfect desktop product for those needing to keep gadgets charged throughout the day. Housed in a tough, aluminium shell that keeps the internals of the spidermonkey cool, the product has a 4-light display to show individually when all 4 USB ports are working and gadgets can be charged.