Replacement Oxygen Sensor. For all Bacharach PCA Combustion Analyzers. Used In Models: 24-8040; 24-8042; 24-8043; 24-8243; 24-8045; 24-8143; 24-8145;and 24-8245. Image shown may NOT be accurate - Some show devices instead of parts; This is a PART, not the whole device. .