This is a decent substitute I️MO, I️ haven’t tried the Hubble, so I️ can’t compare them, but I️ haven’t had any problems using this piece with the DTV4. My only tip would be to inhale after getting the water level to where you like it when filling, otherwise the water kind of just drains out (I️ think it has something to do with the pressure)

Side note: If you have terp pearls, the silicone container that comes with the glass is perfect for holding them