Gibraltar SC-BA78 7/8 Inch Diameter Ball Tom Arm Ball Arm with 7/8" Post The Gibraltar Ball Arm with 7/8" Post is great for mounting toms Adjustable 7/8" tom arm with ball swivel attachment to 10" vertical tube The Gibraltar Ball Arm with 7/8" Post is great for mounting toms Adjustable 7/8" tom arm with ball swivel attachment to 10" vertical tube