Hi Michael6525,
Thanks so much for your feedback.
The complimentary drains which are included with any Kraus stainless steel sink are constructed of stainless steel but do have some plastic parts such as the tail piece and plastic nut.
You can utilize other brands of drains as long as they are compatible with a 3.5 inch sink opening. However according to the feedback we receive from customers, Kraus drains are of a superior quality than what you will find in stores.
Please feel free to call us at 800-775-0703 or email us at customerservice@kraususa.com with any additional questions. We’d be happy to assist you.
Best,
Mike
Kraus USA