An adapter for coupling a disposable water bottle to an endoscope including a cap manufactured from a thermoplastic elastomer material. The cap is removably secured to an associated water bottle. The cap includes a first port and a second port. The adapter further includes a scope connector manufactured from the thermoplastic elastomer and/or thermoset elastomer having a first scope connector port and second scope connector port, wherein the scope connector is configured to be frictionally coupled to an endoscope. A first supply tube couples to the first port of the cap and the first scope connector port and a second supply tube coupled to the second port of the cap and the second scope connector port. By using a thermoplastic elastomer and/or thermoset elastomer material, a simplified adapter is provided, which substantially reduces design and manufacturing costs.