They were making these for the Austrian and other NATO military before they came out with their pistol.
In other words they were a great company before they were gun company.
The grenade has a polymer body with steel ball bearings mixed into the explosive material providing the frag.
They had enough humor to make the Glock 45 a 9mm. I think that making the Glock 44 a .22LR would be pretty cute. However, I don't think it'll happen because it's harder to achieve very high reliability with rimfires. I could see Glock worrying that a bad bucket of bulk .22 would tarnish Perfection.