On the packaging of all Millar Mikro-tip Catheters, there is a year and month listed as pictured in the image below.
This date is the recommended Use By Date for the catheter, and marks the end of a three year period after a catheter's manufacture. The materials used in a catheter's construction degrade over time, and this degradation can begin to affect the functionality of the catheter after the afore mentioned period of three years. For repairable catheters, this date also denotes the end of a catheter's repairable life. If the catheter fails after this time period, there is no evaluation or repair option, even if the catheter fails on the first use.
Note: the manufacturer's warranty period for a catheter is not related to this date and varies between different catheter models. The manufacturer's warranty period begins on the date the catheter is shipped to a customer.