3 in 1 columns are the most versatile columns around.
It is adaptation of the Build-a-columns system. The most typical combination is 8' column cut into 2 pieces. One long tube that would be the length to build a 6' column when you put the cap and base on. add the hidden foam connector with a 2' extension ($15 accessories) to create an 8' column. The third option is to add the cap and base to the 2' extension, which creates a 34" column.
Three columns heights in one:
8' or 6' or 34" all for the cost of one 8' column ($110) and the foam connector ($15).
All are very popular and a cost effective way to have the flexibility for designs without the high cost and storage needs for a huge variety of columns. The parts can even be stored nested together to reduce space.