CCA -- cold cranking amps. You need enough to get your engine to turn ove fast enough to get it started. If you can't hand start the outboard on your M26 and need a backup, you might think about this. These units are essentially a smaller than standard battery, battery charger, and jumper cables bundled together. To recharge the battery you need to plug in to a 110 volt ac circuit -- probably at home. Then you carry the apparatus to the boat. When you get there you have a fully charged small battery. For about the same money, you could buy an inexpensive battery charger and a full sized marine battery. That would be my choice.