The CORE regulator's amazing breathing, which is rated as “superior” on the ANSTI breathing machine, coupled with its generous features, at an attractive mid-range price, provides the best value of any regulator offered today. The CORE comes standard with Aqua Lung's unique, patented, auto-closure device (ACD) which seals water out. Number of models 4 models: CORE yoke, CORE din, CORE Supreme yoke, CORE Supreme DIN Type of first stage Balanced diaphragm design Auto-Closure Device (ACD) Yes Number of HP ports 2 Number of MP ports 4 1st Stage Flow Rate 1450 l/min 1st Stage Weight in DIN 510 g 1st Stage Weight in Yoke 700 g Environmental Dry Kit On Supreme model only First stage exterior Chrome over marine brass Type of second stage Pneumatically balanced Controls Venturi switch Breathing resistance Preset Mouthpieces 2ea. – A Comfobite, installed, and a standard with bite wings in the box Lip shield On Supreme models only Heat Exchanger for freezing resistance Standard on all models 2nd Stage Weight 175 g 2nd Stage Weight – Supreme model 178 g Hose length 730 mm Overall work of breathing (WOB) scores Avg. 0.80 joules/liter Nitrox compatible Yes to 40% O2 when new, out of the box