"Carpet" S1V3 FM -5mm Carbon Fiber Narrow Chassis (Low roll center)**NOTE: For use with V4R, you will need the narrow "Carpet" RF suspension mount. PRR71400626..
Cooling Fan Mount/ Holder 30x30mm (Aluminum Alloy) 1.4g.Fits 30x30mm fan. 30x30 is the basic square size of the fan, bolt spacing is 25mmx25mm.... and it a RC industry standard way of calling out fan sizes...