Katrina found a source to make and sell real leather cell phone cases dyed in different colors. She must pay a fixed manufacturing fee of $60,000 to rent the facility. She must pay fixed insurance and technology costs of $12,000. She pays a material fee of $12 for each unit produced, and a sales commission of $3 for each unit sold. She is only charging $24 per case. How many units does Katrina have to sell to break even?