Wanted to add more bottle volume to my Panthera but didn't like the look of the Panthera without the barrel guard. Saw Saber Tactical's Drop-down front bottle adapter and gave it a try. https://sabertacticalinc.com/products/fx-panthera-drop-down-adapter-st00xx. stainless steel electroplating was nice. Easy to install. Put a slim 300 bar 300cc bottle on the front for a total of 600cc. I didn't want anything too long like a 580 or a 700 cc because my Panthera is a 500. Maybe a 420 would be OK.