The rubber on the top surface of some WFT-E7A units produced in certain lots from April 9 through July 13 may turn white after a short period of time. We have determined after inquiry with the rubber manufacturer and analysis, that the white substance is zinc bis (N,N’-dimethyldithiocarbamate).
Zinc bis is not used in the production of this product. However, the quantity of rubber accelerator used in the affected production lots was slightly higher than usual. As a result the rubber surface may turn white due to a chemical reaction with the rubber accelerator and other substances. High temperature and high humidity may contribute to this condition. Zinc bis (N,N’-dimethyldithiocarbamate), which becomes deposited on the rubber surface, is created as a result of this chemical reaction.
Only certain WFT-E7A wireless file transmitter units
produced between April 9 and July 13, 2012 are affected.
If the first two digits of the serial number are “03” through “06” and the fifth digit is “1”, the unit is affected.
03xx1xxxxx, 04xx1xxxxx, 05xx1xxxxx, 06xx1xxxxx ([x] represents any optional number. )