From the tear edges that looks like a carbon crank. Aluminum FSA cranks here:

http://www.fullspeedahead.com/produc...ANDEM-CRANKSET

If crank length matters to you, look at the options on the cranks you buy. Some brands have very limited options in tandem cranks.

Also both Shimano and FSA may leave you stranded. I had FSA 170s captain cranks and needed a replacement. FSA no longer makes them in that length. Shimano left the tandem crank market for quite a while and now is back. Who knows how long they will make tandem cranks before they once again decide the volume is too low and discontinue production.