This is a in sump model. Here are some specs on it from the company.
Overall Nautilus TE height 23” or 58 cm
Widest Nautilus TE width 8¼” or 21 cm
Recommended pump flow rate 650-900 gph or 2,461-3,407 lph at 0’ head pressure
Maximum recommended aquarium capacity 300 gallons or 1,136 liters...