This is a 19V fixed-voltage MyVolts-branded power supply adaptor designed to meet exactly the power specification of your Asus S551LB Laptop.Specifications: – Output voltage is 19V – Max. output amperage is correct for your device – Output tip is the right size and specification – we’ve tested it thoroughly – 2-pin plug for use with the Type C (EU) wall sockets – Input voltage is AC100-240V, 50/60HzIn addition, this myVolts-branded replacement power supply for Asus S551LB Laptop is: – Compliant with all safety standards, and features overvoltage, overcurrent and short-circuit protection to protect your device from damage – RoHS and CE-certified – Energy Star level 6 approved, guaranteeing more efficient delivery of power to your devices, at less cost to you – Covered by a 2 years’ warranty: if the power supply fails within 2 years from the date of purchase, we’ll replace it, no worries.