Manfrotto 088LBP Adapter 1/4-Inch- 20 to 3/8-Inch with flange
Adapter 1/4- Inch- 20 To 3/8- Inch With Flange. Attachment: 1/4- Inch female thread; attachment 2: 3/8'' screw; black color; diameter: 1.18 in; material: nickel steel; weight: 0.11 lbs.