This is an adaptor to enable one to connect commonly available small animal bottles with a flat mount to a rounded home barrel for mice (Oggi 130 oz. clear acrylic barrel).  Rounded barrels are preferred when using a commutator/tether. The dimensions of the holder and screw holders is idea for the Choco Nose H125 drinking bottle.  Please note that when using this drink bottle with mice that occasional jamming is possible.  Ensure that the water level is half way up the bottle (prevents suction jam) and also remove one of the two stainless steel balls to make it easier to depress the ball valve.  Cage floods have not occurred, but if bedding comes into contact with the lickset this is sure to happen.