I purchased two;
Hard to tell size but the firs is about 1/2 the size of the second. The second is standard backpack size. The first will handle an Ipad and other stuff, the second, Ipad, Iphone, two readers, and lots more.
The first is a smaller bag for tours. We cruise. This bag is for sunscreen, cameras, Ipads, towels, repellent, and such. It is also for DW's purse on flight's, and other day travel. It is much smaller than the second bag.
The second is for air travel and short trips. I carry it along with a carry on roller. These two are all we need.