Solid magazine with a few considerations - Magpul Industries PMAG GL9 Glock 17/19/26/34/45 9mm Luger 21 Round Pistol Magazine

The Magpul Glock pattern magazines are solid. The biggest thing to be aware of though it that they are a little more sensitive to dust than factory magazines that have the steel inner. Having said that they are much easier to disassemble and clean because they don’t require a magazine tool. Their cost is also a huge advantage. I can get 3 Magpul 21 round mags for the price of Glock factory magazines with +4/5 extension baseplates.