Bat Company's flexible budget for the units manufactured in May shows $15,800 of total factory overhead; this output level represents 70% of available capacity. During May, the company applied overhead to production at the rate of $3.00 per direct labor hour (DLH), based on a denominator volume level of 5,940 DLHs, which represents 90% of available capacity. The company used 6,000 DLHs and incurred $16,400 of total factory overhead cost during May, including $7,700 for fixed factory overhead. What is the variable overhead efficiency variance for May under the assumption that Bat uses a four-variance breakdown (decomposition) of the total overhead variance? (Round your intermediate calculations to 2 decimal places; Round your final answer to zero decimal places.)