Hello Mauricio, this mask already comes installed with the 2nd stage regulator. As for your 1st stage yes you can use that with this. If you want to install your own regulator in the mask you would need to order the Ocean Reef Neptune II Full Face Scuba Dive Mask Only web link: http://www.scuba.com/scuba-gear-124/027360/Ocean-Reef-Neptune-II-Full-Face-Scuba-Mask-Only.html
. If you would like to place an order or have any other questions please feel free to give us a call at 1.800.347.2822.