Welcome to GOY Jennyt19. I have this called "Rosy Bells" I planted it late last year the packet says up to 25cm. I have some which should grow to 140cm so this is quite small.

About 9 inches. Watch out though this is a terrrible seed weed. It spreads, so dead head after flowering!

Thanks for the tip Owdboggy. The fact that I got 25 of them for the same price as one larger allium should have alerted me. I will dead head

Well, just to put them in perspective, I weeded out over 10,000 last year and still we got some coming up!