Products Name:Geeetech Reprap Ramps1.4 RRD Fan Extender For 3D Printer Reprap With 2 Channels Description: - If you build or upgrade your printer with/to DUAL-EXTRUSION (2 extruders) including a heated bed all the output ports (D8, D9, D10) will be used. In this case, there is no option to connect a firmware controlled FAN to RAMPS board directly. However, in Sprinter/Marlin firmware there is an option already (Marlin: BOARD=34) which redirects the FAN to RAMPS output D4. But this solution needs a "buffer/driver" in order to work. - The RRD-FAN-EXTENDER is exactly what you need in this case. It is a plug and plays solution to mount the FAN for DUAL-EXTRUSION setups with RAMPS1.4. But instead of adding only one additional output port the RRD-FAN-EXTENDER is equipped with 2 PWM controllable channels(D6/D11). The second channel can be used for another fan(e.g. to cool the stepper driver) or for adding light control (e.g. add dimmable LED light to your machine). Specifications: - Support Max 20V - 2 (PWM controllable) channels (D6/D11) - Easy to install, Plug and Play - Support per channel Max 0.5A, enough for a big fan - Flexible output voltage (you can connect the RRD-FAN-EXTENDER to 12V,5V,... in order to support the output voltage you need) - Already supported by Marlin firmware (choose " define MOTHERBOARD 34") - Easy to adapt to other firmware (e.g. Sprinter: just change " define FAN_PIN 6" in "pins.h") Features: 1. You need Marlin firmware v3 or newer. If you are using the older firmware, you must re-flash your board. 2. Power up, two connecting fans will take turns to rotate. 3. Can be connected follow the description picture. Package included: 1 x Reprap Ramps1.4 RRD Fan Extender