There are two flavors:
The first kit costs $487.99 and the second kit $559.76 at Mushkin's webstore.XP2-6400 with 4-3-3-10 latencies, 2.2V XP2-8500 with 5-4-4-12 latencies, 2.3V
The first kit costs $487.99 and the second kit $559.76 at Mushkin's webstore.XP2-6400 with 4-3-3-10 latencies, 2.2V XP2-8500 with 5-4-4-12 latencies, 2.3V