Master Lock & Key Store in Castro Valley , CA is made of Quality and Professional Locksmiths, chosen by hundreds of homes and businesses, government and state departments as preferred Locksmith Service provider. All our Locksmiths work with the highest standards and best tools available, providing Locksmith Service around the clock. Our Local Locksmiths in Castro Valley , CA are on call 24 hours a day, 7 days a week waiting to service you. With 20 minutes response time, we'll be sure to provide you the Best Locksmith Solution in the Fastest Way Possible.