The proposed drum magazine shall have a capacity of not less than 30 cartridges. The proposed magazine viewing apertures arranged at 10-round intervals shall indicate loaded conditions. The proposed magazine shall conform with 3.2.2.2 performance requirements.

The SMG 1 was a prototype developed by Heckler & Koch in an attempt to improve upon the iconic MP5.

I can’t be the only one who thinks this thing looks like it should shoot lasers.

https://www.thefirearmblog.com/blog/2015/11/06/weird-magazines-vol-iii-the-heckler-koch-transverse-smg-i-mag/

https://smallarmsreview.com/archive/pdf_selector.cfm