Leofoto Outdoors Ball Head w/ Elongated Control Knob Arca Black. The head features an elongated knob for easy locking and unlocking of the ball accompanied by a smaller tension control knob. The elongated knob is the perfect length to be used with a rifle clamping mount to not interfere with the large mount. The clamp is Arca compatible. The MK-40X is the ideal partner head for the Leofoto GS-3 Rifle Clamp. Specifications for Leofoto MK-40X Outdoors Ball Head w/ Elongated Control Knob: Manufacturer: Leofoto Color: Black Attachment Type: Arca Features of Leofoto MK-40X Outdoors Ball Head w/ Elongated Control Knob Aluminum CNC Machining Package Contents: Leofoto MK-40X Outdoors Ball Head w/ Elongated Control Knob Leofoto MK-40X: MK-40X Outdoors Ball Head w/ Elongated Control Knob Arca Black