In contact with the patient an ultrasonic array of any shape extends the hand of the physician when he is conducting visual examinations using echography. He continually becomes familiar with the device and with the produced images.If we look at the internal structure of the different types of array, such as the curved one, the endoscopic, or the phased arrays we can see that they are all examples of superb technological integration, driven by a very demanding and competitive market.The quality of the images and the level of visual errors depend directly on the spatial distributions and time response of the ultrasonic beams. This must be described in terms of precise specifications for the operation of each transducer which make up the array, and also for the cross talk between adjacent elements and for the array homogeneity. The different stages of array manufacturing will be described:* modelling and computation of radiation patterns and time response;* selection and processing of the piezo-electric materials;* micromanufacturing, cabling and integration in the probe housing.This presentation also demonstrates the compliance of these devices with electrical safety standards, acoustic output limitations and with sterilization and reliability requirements.Take care of these devices, as they include a lot of know how and technology!