Mesa Labs produces a hand held diagnostic device used to calibrate dialysis equipment. The customer was interested in having a medical probe assembly part of the diagnostic device, encapsulated in a rigid material. Based on the requirements for the rigid material, and the customer's need for several hundred units to be produced annually, it was determined that the liquid resin casting process was the most economic and productive method to use. A cast epoxy mold was constructed to hold a machined plastic tube and rubber strain relief in place as the assembly is encapsulated by the cast urethane material.