Here are a couple of Laptop Adapter options for your Acer Predator Helios 300 that should serve you well: The Replacement Cpu Cooling Fan For Acer Predator Helios 300 G3-571 G3-571G DFS541105FC0T FJN1 DC5V Series Laptop for R750 is a direct replacement for keeping your laptop running cool. The Ac 19V 4.74A Charger Adapter For Acer Laptop Output Tips: 5.5MM X 1.5MM Black for R509 will ensure you can keep gaming and working on the go with a reliable charging solution. Both came up directly in the search results and seem perfectly matched to fit your Acer laptop. Please let me know if you need any other details!