250W 250 Watt Power Supply for HP 5187-1098 Bestec ATX-250-12Z Desktop PC System Fans: 1 Main Connector: work on both 20 pin and 24 pin motherboard Efficiency: 70% Min. at full load MTBF: 100,000 hrs at ambient conditions Dimensions: 5.9 W x 3.9 H x 5.5 D - Inches