DDR4 RAM with a storage capacity of 4GB and a frequency of 2400T from SK hynix, made in China. And DDR3 RAM with a storage capacity of 4GB and a frequency of 12800S from SK hynix, made in Korea. Serious buyers, please contact via WhatsApp for inquiries. Your questions will be answered. The RAMs are working fine, no issues. The reason for selling is that the laptops were upgraded to higher capacity RAM. You can test them upon purchase, guaranteed.