This is the ScubaPro MK17 EVO 1st Stage Scuba Diving Regulator

Features:

• Balanced Diaphragm 1st Stage Design
• Two HP Ports
• Four LP Ports, 2HF, 2-Standard
• More Compact Streamline than Predecessor
• Environmentally Sealed
• Dry Ambient Pressure Chamber
• Favored Choice of Cold-Water Divers
• Machined Marine-Grade Chrome Plated Brass
• Thermal Insulating System (TIS)
• TIS: Prevents Freezing-Up and Malfunctioning in Cold Water Conditions
• Weight: 30 oz. (850 g)
• LP Hose Not Included

The new MK17 EVO is Scubapro's premium high performance balanced diaphragm first stage. Engineered specifically for cold water and harsh environments, its internal components are completely sealed off from the elements so neither water nor pollution can get inside the chrome-plated marine grade brass body to foul the mechanism. This total sealing system also allows for a dry ambient pressure chamber which works to prevent freezing, provides better protection and improves performance, ensuring trouble-free operation no matter how cold or murky the water gets. This new version is more compact than its predecessor yet delivers better breathing performance. Its improved internal design allows more airflow from the LP ports which have also been configured for optimum hose routing.