This might help, re muffin fan
AC Infinity AXIAL LS1238, Quiet Muffin Fan, 120V AC 120mm x 38mm Low Speed, UL-Certified for DIY Cooling Ventilation Exhaust Projects
https://www.amazon.com/gp/product/B07CZRKTBZ/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1