Magpul has been killing it in the dependable 50- and 60-round drum business in the past few years. Sure, these types of mags have been around for decades, but Magpul’s actually work, so there’s that.
The three newest in the collection– all priced at a “they cost what they cost” $124– are 50 rounder 9mm drums for Glock pistols, MP5 style clones, and PCCs that accept Glock patterns.
Like their M4/AR and EVO9 drums, they all have a ratcheting lever, high viz follower, and clear rear witness window.