Anyone know how to make attachment points

Anyone know how to make attachment points

Iv started making models im starting with simple attachments, can somone tell me how to make attachment points ¿ ¿

Which program do you use?

GMax,i got ir from a page with warcraft map editor page

By the way i like your cannon model.

I don't remember how to do in gmax. But try with magos editor.

I made no cannon model.