SEIKO SEIKI STP-451C LOW FIELD TURBOMOLECULAR PUMP w SCU-301 CONTROL UNIT, CABLE. Model: STP-451C Low Field/ SCU-301. Type: Turbomolecular Pump with Controller and cable. Note: You will receive the actual unit shown. Inspection is available, or if you’d like us to perform further tests/checks, please write to us with your set of instructions.