PROTO, 1/4 in_3/8 in_1/2 in Output Drive Size, Square, Socket Adapter Set - 19C375|JHA4S - Grainger
1/4" to 3/8" Thread Adapter
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
Threading Adapter, NPT 1/4 Female to NPT 3/8 Male
Dinkum Systems Adapter Screw - 1/4" to 3/8" 3075 B&H Photo Video
Husky 1/4 and 3/8 in. Drive Adapter Set (3-Piece) HADPTR3PC - The Home Depot
Manfrotto 015 Adapter 1/4" - 3/8" – Thomann United States