There are many different types of cable clamps to choose from, the real differences between them are based on what you need the clamps for. Some are simple O-shaped plastic with an adhesive bottom, perfect for disentangling speaker wires and computer cables. Others are a more heavy-duty "clamp-style," coming in solid aluminum, with two plates that are screwed together. The plates have V-shaped indentations made for 18-gauge wire or other sizes depending on the model. Some come with magnets for mounting on metal surfaces. Yet another kind of cable clamp is the same kind of tool used in jumper cables to connect the cable to the battery, an over-sized "alligator clip".
If you need to shop for cable clamps, it's a very good idea to bring a picture or spare clamp with you when trying to locate them in the store. There are so many definitions for this particular tool that you may need to show a clerk or sales rep before they will know exactly what you need.