Brandon, several manufacturers do. You can use buds search and type in " Glock 43X magazine " and any of those will fit. Glock 43X magazines also fit Glock 48. Or here's a link to a 19 round magazine that will fit made by ets................. budsgunshop.com/product_info.php/products_id/411559181/ets+fits+glock+43x+48+-+19rd+9mm+mag............... And here's a 30 round drum mag that will also fit.............. budsgunshop.com/product_info.php/products_id/125122/promag+drma35+for+glock+9mm+luger+43x+48+30rd+black+drum................ Hope this helps.

Brandon, ProMag makes a 15rd magazine for the G48. budsgunshop.com/product_info.php/products_id/714025797/promag+for+glock+48+9mm+15rd+blue+steel ....and a 50rd drum budsgunshop.com/product_info.php/products_id/122836/promag+drma20+for+glock+compatible+9mm+luger+fits+g48+43x+50rd+black+polymer+drum />

ETS offers some of the best Glock magazines on the market. Their transparent smoke polymer enables you to see your rounds making for a stunning visual. These magazines have been torture tested without fail.
Fits the Glock 43x and 48
ADVANCED POLYMER BENEFITS
Extreme Impact Resistance - Won't crack or break when dropped
Very resistant to harsh chemicals Superior heat, cold and UV resistance - Won’t become brittle over time even when exposed to harsh environments or extreme cold
Translucent body - Allowing you to see your ammo count and type
Creep resistant - The feed lips and body won't spread when being stored long term even when fully loaded
Brand: Elite Tactical Systems
Caliber: 9mm Luger
Capacity: 19-Round
Material: Polymer
Fits the Glock 43x and 48
Compatible with Gen 4/5 Glocks
19 round capacity
Compatible with Glock and aftermarket floorplates
Easy disassembly with our specially designed baseplate
Ergonomically designed floorplate makes it easy to grab from mag pouches.

Brandon, there are various magazine extensions available for extra capacity (Example) : glockstore.com/4-Magazine-Extension-for-G43X-48?quantity=1&custcol9=527