Massacher

This is the one I have in my system now. 2x8GB. https://www.scorptec.com.au/product/memory/ddr4/60345-cmk16gx4m2b3200c16 I'm going to get another 16GB but its SKU is different. https://www.umart.com.au/product/corsair-16gb-2x8gb-cmk16gx4m2e3200c16-vengeance-lpx-3200mhz-ddr4-ram-52111 cmk16gx4m2b3200c16 vs cmk16gx4m2e3200c16 2b vs 2e What do those letters signify? Is 2e newer or what does it mean?