Explain more about this case study, how do they get the LTL from i dont understand

Big Bob's Axles has a customer that requires axles with a diameter of 25cm0.02cm. The customer has stated that Big Bob must be able to meet these requirements 99.7% of the time in order to keep the business. Currently, Big Bob is able to make axles with a process mean of exactly 25cm and a standard deviation of 0.005cm. Is Big Bob capable of meeting the customer's needs? Notice that the UTL and LTL are 25.02cm and 24.98cm, respectively. Therefore, the process capability ratio is: Cp=6UTLLTL=6(0.005)25.0224.98=0.030.04=1.33 Because the process capability ratio is greater than 1 , Big Bob's process is more than capable of providing 99.7% defect-free axles