Electric Zero produces relay units for generators. Each relay has a standard cost of 96?. 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 four relays damaged in the installation process. The standard quantity of labor is 20 hours per generator, with a standard wage rate of $23. In July, the company incurred 1, 020 labor hours at a cost of $22, 960. How much is the labor efficiency variance