Leofoto Lever-Release Hybrid Clamp Ball Head Arca/Picatinny Black. An over-sized ergonomic locking knob allows 45-degree tilting in all directions and a 90-degree drop-notch facilitates quick and accurate switching from the horizontal to vertical orientation. A separate tension knob is provided to apply the appropriate pressure that safely corresponds to the weight of your firearm. A third knob loosens and locks the panning base which is laser-engraved with markers every 2.5 degrees from 0 to 360 degrees. The redesigned hybrid clamp allows for both arca and picatinny rails to be attached with an hex screw for adjusting the width of the clamp for any non-standard picatinny and arca sized rails. Specifications for Leofoto LH-40LSC Lever-Release Hybrid Clamp Ball Head: Manufacturer: Leofoto Color: Black Attachment Type: Arca Features of Leofoto LH-40LSC Lever-Release Hybrid Clamp Ball Head 3/8'' Mounting Stud Precision Scale for Positioning Diameter: 100mm (Compatible with 100mm Bowl Tripods) Bubble Level Adjustment Range of +/- 15degrees Package Contents: Leofoto LH-40LSC Lever-Release Hybrid Clamp Ball Head Leofoto LH-40LSC: LH-40LSC Lever-Release Hybrid Clamp Ball Head Arca/Picatinny Black