The SP-RM250 Robust Mount Shaft is part of Arkon's Robust Mount Series and can be used with 25mm 1 inch-compatible mount bases and heads to create your own custom mount solution. This includes only the Mount Shaft holders and adapters sold separately with tightening knob. The mount shaft measures 3. 75 tall and along with your choice of mount head and base sold separately, is ideal for creating a mount solution with double ball adjustment points. Use Arkon's adapters to create either a 4-Hole AMPS Model APAMPS25MM or suction mount Models SPRM079 or SPRM080 base, and a Dual-T Model APRM2T, 4-Prong Model SP25MM4P, 1/4-20 camera Model SP142025MM, lateral GoPro Model SP25MMGP, VESA pattern Model AP25MMVESA, or 4-Hole AMPS Model APAMPS25MM mounting pattern head.