Structure of a golf club head or other ball striking device

A ball striking device, comprising:

• a first member including a first surface that, at least in part, defines a ball striking surface that faces a ball in use;
• and
• a second member attached with the first member, wherein the second member includes a body portion that extends in a direction away from the first member, wherein the body portion defines at least one open area,
• wherein the ball striking device includes a ball striking head that includes the ball striking surface, wherein the ball striking head has a moment of inertia about a center of the ball striking surface of at least 10,000 g/cm2.

A golf club head, comprising:

• a first member including a first surface that, at least in part, defines a ball striking surface that faces a ball in use;
• and
• a second member attached with the first member, wherein the second member includes a body portion that extends in a direction away from the first member, wherein the body portion defines at least one open area,
• wherein the golf club head has a moment of inertia about a center of the ball striking surface of at least 10,000 g/cm2.

A method, comprising:

• providing a first member including a first surface that faces a ball in use, a second surface defining an opening, and a base member extending in a direction away from the first surface;
• inserting an insert portion of a second member into the opening defined in the first member, wherein the second member further includes a body portion that extends in a direction away from the insert portion, wherein the body portion defines at least one open area;
• and
• securing the first member and the second member to one another.

A method, comprising:

• providing a first member including a first surface that, at least in part, defines a ball striking surface that faces a ball in use;
• and
• securing a second member with the first member, wherein the second member includes a body portion that extends in a direction away from the first member, wherein the body portion defines at least one open area,
• wherein the first member and the second member, at least in part, form a ball striking device, wherein the ball striking device includes a ball striking head that includes the ball striking surface, wherein the ball striking head has a moment of inertia about a center of the ball striking surface of at least 10,000 g/cm2.