what are the requirements for making the rams horn that is blown on Rosh hashana?

There is a great deal of symbolism tied in with the legal requirements for what constitutes a proper shofar. The shofar of Rosh Hashanah, whose purpose it is to rouse the Divine in the listener, may not be constructed of an artificial instrument.It should be from a ram or other clean animal. It must be an instrument in its natural form and naturally hollow, through whom sound is produced by human breath, which God breathes into human beings. This pure, and natural sound, symbolizes the lives it calls Jews to lead. The most desirable shofar is the bent horn of a ram. The ram reminds one of Abraham's willing sacrifice of that which was most precious to him. The curve in the horn mirrors the contrition of the one who repents.

correct!