Not secure
It’s a $100 shaped piece of foam. Also, the trolley handle it clasps onto gets loose due to design flaws, meaning that the seat itself will also feel loose. That and the fact that it’s not that viable to sit on the v11 with Clark pads or while being 6ft tall. It just doesn’t work that well due to the thing it grips onto (also, the Velcro’s adhesive peels off both surfaces). Overall, this isn’t a really serious product from them.