My preference is to go with the connectors; they are called various names, master link, quick link, power link, etc. You need to match the size of the link to the chain; 7-speed, 9-speed, etc. The connectors can be opened and closed without a special tool although tools are available and are convenient. You will still need a regular chain tool to cut a new chain to the proper length. If you decide to go the one-use pin route they must also match the chain you are closing. Buy a few, you will need a new one each time. As mentioned above don't open the same link twice.