I’ve seen and used the HandySitt portable seat before — you often see it in restaurants here in London. But I had no idea that it is a part of a bigger highchair system. Combined, the Minui HandySitt Chair and portable seat form a freestanding high chair. When detached, the chair is a seat for older kids and/or a sturdy step stool… and the Portable Seat is ideal for travel or for restaurants, etc. Pretty handy if you ask me!