It depends on the panels. Yes, you can chain the Boulder 100 Briefcase with other Boulders that have an 8mm input or input connector, like the Boulder 50 or the older Boulder 30, by inserting the 8mm blue-ringed connector of the Boulder 100 Briefcase into the 8mm input of the other Boulder Solar Panel. When chaining Boulder Solar Panels in configurations over 150W, you’ll need to purchase a combiner cable from Goal Zero.