We use this at our business since we always need to have pen on the desk but we really want to be able to buy the refills. We used to be able to purchase them at Staples but have not been able to for a long time.
The chain has two ends held together by a linking piece as shown in Staples' product's picture. Note that the chain is more of a mental device to keep your pen from being further from where you put it than you want. Meaning if someone wants the pen all they'd have to do is pull hard or unlink the joint holding the two ends of the chain. You may have seen this linking piece holding a necklace or bracelet together.
It not by any stretch a "nice" pen. It is a pen that will be there when you need it. In our office we affix them to clipboards for patients who need to fill out paperwork. Before we were going through about 2 dozen pens a week that walked away. These are always there when we need them. I (like other reviewers) would prefer a refillable pen. You can buy the entire pen as a replacement (without the chain & sticky part) but when they are on sale you can buy the entire item again for less than the pen replacement.