Question about Corsair Vengeance LPX

What is the difference between these 2: CMK32GX4M2 D3000C16 for 180.- CMK32GX4M2 B3000C15 for 249.- both are "Corsair Vengeance LPX (2x, 16GB, DDR4-3000, DIMM 288)". 70.- Difference only for 1ms latency?