In this paper we examine the effect of different brands of highly-coercive permanent magnets on the basic parameters of leaks protection equipment with a cylindrical magnetic coupling (angle of deviation of the coupling halfs, the power loss in a conductive screen, the temperature rise of the screen above the ambient temperature and the required flow rate of coolant water for the screen cooling) while preserving the main indicator - the value of the transmitting torque of the magnetic coupling. Dimensions of the magnetic coupling and coupling halfs when different grades of permanent magnets are used remain unchanged.