Metcal 3rhb 700 series receiver head assemblies 3ft hose metcal 903 3rhb a receiver head assembly providing the connecting link between the timepressure controller and a 3cc syringe assembly it provides a safe connection for accident proof dispensing the receiver assembly consists of a receiver head with o ring tubing and a male quick connector metcal 903 3rhb 700 series 3cc receiver head assembly 3ft hose