The CENTRAL SEMICONDUCTOR CBAT54 Series types are Silicon Schottky Diodes in an SOT-23 Surface Mount Package.
CBAT54: SINGLE MARKING CODE: CL4
CBAT54A: DUAL, COMMON ANODE MARKING CODE: CL42
CBAT54C: DUAL, COMMON CATHODE MARKING CODE: CL43
CBAT54S: DUAL, IN SERIES MARKING CODE: CL44