Brass, 3/8 in x 1/4 in Fitting Pipe Size, Reducing Adapter - 46M454|706120-0604 - Grainger
4pcs Durable Male to Female Screw Adapter 1/4" 3/8" Mount Set Thread Screw Adapters Convert for Camera Tripod Light Stand - AliExpress
Amazon.com : Camera Screw Adapter Thread 1/4" Male to 3/8" Female and 3/8" Male to 1/4" Female Adapter Set for Camera Monitor, Tripod, Mount : Electronics
CRAFTSMAN 3/8-in to 1/4-in Standard Socket Adapter in the Socket Adapters department at Lowes.com
Everbilt 1/4 in. OD Compression x 3/8 in. Flare Brass Adapter Fitting 800779 - The Home Depot
Everbilt 3/8 in. Flare x 1/4 in. MIP Brass Adapter Fitting 801539 - The Home Depot
Amazon.com: Niewalda 1/4 Inch Male to 3/8 Inch Female Tripod Screw Adapter 3 /8 to 1/4 Tripod Adapter Mount Screws, Accessories for Camera/Tripod/Monopod/Light Stand : Electronics
1/4'' to 3/8'' screw thread converter-adapter | TeleprompterPAD.com
Husky 3/8 in. Female to 1/4 in. Male Drive Adapter HADPTR3814 - The Home Depot
Husky 1/4 and 3/8 in. Drive Adapter Set (3-Piece) HADPTR3PC - The Home Depot
3/8-24 to 1/4-20 Stainless Steel Adapter GigaParts.com
Threading Adapter, NPT 3/8 Male to G 1/4 Female
Adapter 1/4" Female to 3/8" Female – Modern Studio Equipment.
Brass Adapter, Male (1/4-18 NPT), Female (3/8-18 NPT) – AGS Company Automotive Solutions