The L-1B visa is a non-immigrant visa that allows companies to transfer employees with specialized knowledge from a foreign office to a U.S. office. This visa is specifically designed for employees who possess unique skills or expertise that are essential to the company's operations in the United States. To qualify for the L-1B visa, the employee must have worked for the company for at least one continuous year within the last three years. The employer must demonstrate that the employee's specialized knowledge is critical to the business, ensuring that the transfer benefits both the company and the U.S. economy.