This is a set that the previous owner ordered to balance out the sound on his CD player. MK3 cones has a warmer, more bassy sound while the MK4 adds a bit more detail and upper end extension. There are two MK3 cones and one MK4 cone in this set. Each cone is about 1″ tall and about 1.6″ wide with 1/4″-20 thread (included are three threaded rises). Depending on what component you intend to use it with, typically, when in use with CD players, the cones should be pointing downwards. For other components, it should be pointing upwards towards the component (that is the flat surface of the cones should be sitting on the shelf with the pointed tip resting under the component.
Cosmetically, they are in very nice shape. Minor scuff marks common with use but nothing major. They will be securely packed for safe shipping.