For your question, we would like to have below suggestion:
In general, goods imported into and sold in Vietnam are subject to import duty and VAT. Some kinds of goods are subject to special consumption tax as well. However, pursuant to The Law on special consumption tax, your products are not subject to special consumption tax.
Import duty is implemented according to MFN import export tariff schedule enclosed with Circular No. 157/2011/TT-BTC dated 14/11/2011 by the Ministry of Finance, effective from 01/01/2012.
VAT is performed in accordance with provisions in Circular no.06/2012/TT-BTC dated January 11th 2012 of Ministry of Finance.
You can find the mentioned documents on our website: www.customs.gov.vn
Best regards,