Seller does not provide dimensions of water block fittings. The connectors fit 3/8" hoses perfectly. The "main board" is not as shown, it is a thicker 5mm x 12mm bar. The black grommets provide thermal insulation between the hot radiator and the colder one Water block Fan mount Screws are used to grip the heatsink between the fins but will not fit the motor mounting holes The motor mounting holes require a slight raise The fan is DC 12V 0.09A The heatsink is for a 40mm x 40mm 40mm water block well suited it can fit up to 45mm x 49mm and less than the heat transfer requirements of this system as it has to transfer both 72 watts from the peltier and the heat extracted from the water block Overall a good DIY Deal.