Electric Zero produces relay units for generators. Each relay has a standard material cost of $67. Standards call for two relays per generator. In July, the company purchased 120 relays for $7,560. The company used 104 relays in the production of 50 generators, with 4 relays damaged in the installation process. The standard quantity of labor is 20 hours per generator, with a standard wage rate of $23. The company incurred 1,020 labor hours at a cost of $22,950. How much is the material quantity variance?