Product #2 (Taq DNA Polymerase Kit) consists of three tubes packaged together for retail sale as a set. Tube 1 has Taq DNA polymerase mixed with a storage buffer (see Product 1). Tube 2 has a 10X reaction buffer and its composition is consistent with Product 1. Tube 3 is a mixture of water, dATP (CAS # 1927-31-7), dCTP (CAS # 02783-51-7), dGTP (CAS # 93919-41-6) and dTTP (CAS # 18423-43-3).
Product #3 (Taq DNA Polymerase Pre-Mix) is a pre-mix solution including Taq DNA polymerase, water, KCL, Tris HCl, Tween 20, MgCl2, dATP, dCTP, dGTP, and dTTP in a tube. Five tubes are packed together for retail sale.
[1] Please importantly note that only the relevant portion of the related is displayed above. You may refer to the said customs ruling for the entire ruling explanation.
[1]. https://rulings.cbp.gov/ruling/N313622