Model Wattage Amperage @115v Control Range Water Volume*
HMA-50s 50W .45A 68°F - 92°F 10-20 Gallons
HMA-100s 100W .9A 68°F - 92°F 20-30 Gallons
HMA-150s 150W 1.35A 68°F - 92°F 30-60 Gallons
HMA-200s 200W 1.8A 68°F - 92°F 60-80 Gallons
HMA-300s 300W 2.7A 68°F - 92°F 80-100 Gallons
HMA-500s 500W 4.5A 68°F - 92°F 100-120 Gallons

*Rating for standard enclosed aquarium with a max heating capacity of ± 8°F above ambient room temperatures.