This is the Ultimaker temperature sensor (version 1) that is based on the AD597. It amplifies the signal from a type K thermocouple and has the same mV/K output as the polular AD595 board that is used in many RepRap projects. It's about the size of a thumbnail (hence the out-of-focus picture). The amp chip is an SOT-8. The screw terminals are extra small (2.54 mm pitch) and holes are M3.They were designed in Eagle CAD by Siert Wijnia and myself. The files are found here on the RepRap wiki: http://www.reprap.org/wiki/File:Thermocouple_board_v0.4.sch http://www.reprap.org/wiki/File:Thermocouple_board_v0.4.brdIt has a nice bright blue LED, great for long exposure photography of a print (for moving head machines). The picture with the lit LED is a prototype made with the help of Jelle, who's also designer of the UltiRouter: http://www.thingiverse.com/thing:7110Separate sensor boards (pre-assembled) will be available within a month or two. On request we can also offer the PCBs in quantities of 20 and more.FIXES in the next release:From the outside to the inside of the board, the connections are labeled: -, + and S on the side that goes to the main PCB, on the thermocouple sensor side they are labeled + and -.For instructions on how to hook them up to your analog inputs, please see this page: http://www.reprap.org/wiki/Ultimaker%27s_v1.5.3_PCB#Add-ons