Amazon.com: Noctua NA-IS1-12 chromax.Black Sx2, Inlet Side Spacers for 120mm Fans (Black) : Electronics
120mm PC Radiator Fan Shroud Set of 240mm Radiator Fan - Etsy
Antminer 120mm Fan Spacer 50mm | eBay
120mm fan spacer" 3D Models to Print - yeggi
3 printed fan spacers/shroud. I was able to remove the humming sound of my pc using these. I live in a tropical country so my ambient Temps here would average 38-45 degrees
Fan Spacers (120mm & 140mm) by The3Designer | Download free STL model | Printables.com
SoCas PadMod Spacer for Stax SR-207/507 — SoCas 3D
Amazon.com: Noctua NA-IS1-12 Sx2, Inlet Side Spacers for 120mm Fans : Electronics
Computer Fan Spacers - 120mm-140mm by AEDesigns - Thingiverse
Noctua Na-is1-12 Sx2 5mm Thick Side Air Intake Spacer Frame For 120x25 Mm Fans For Simple And Efficient Fan Noise Reduction - Pc Components Cooling & Tools - AliExpress
140mm Desktop Fan Spacers - 12,22mm by Rhoboto | Download free STL model | Printables.com
Phobya Shroud Plexi (Acrylic) for 120mm Fan - Walmart.com
Fan Gaskets - Fans & Accessories ModMyMods.com - PC Watercooling Parts and Accessories