Hello@ster,
The S5735-L48T4S-A supports stacking using 1000BASE-X ports, If electrical ports or 100/1000BASE-X ports are used as stack ports, a switch supports a maximum of two logical stack ports, and each logical stack port supports at least one stack member port and at most eight stack member ports. A switch supports a maximum of 16 stack member ports. The number of stacked switches is recommended to be 2 to 9. Log in to the web NMS and choose Configuration Area > Advanced Services> Stack.
Hope to help you!