I bought this for mine. And works. Quite. Had to buy a brick but no biggie. SCCCF Quiet 120mm USB Fan, 5V USB Portable Cooling Fan for Flat Panel TV Receiver Router DVR Playstation Xbox Computer Cabinet Cooler https://www.amazon.com/dp/B08ZSJFNMS/ref=cm_sw_r_apan_glt_fabc_DXPP6S4HT5KK37V38XWC?_encoding=UTF8&psc=1
I just bought this and place the modem on top. Made sure the fan blew up first before placing it on top. SCCCF Quiet 120mm USB Fan, 5V USB Portable Cooling Fan for Flat Panel TV Receiver Router DVR Playstation Xbox Computer Cabinet Cooler https://www.amazon.com/dp/B08ZSJFNMS/ref=cm_sw_r_apan_glt_fabc_TRB18JKN3FD0ASFV2V64?_encoding=UTF8&psc=1