Core Specifications

Input Voltage: Universal AC 100V–240V, 50/60 Hz (suitable for global use).
Output Voltage: 9V DC (regulated).
Max Output Current: 2.0 Amps (2000mA).
Total Output Power: 18 Watts ( $9\text{V} \times 2\text{A}$ ).
Standard Barrel Jack Sizes: Most commonly 5.5mm x 2.1mm or 5.5mm x 2.5mm.
Polarity: Standard models are Center-Positive (+ inside, - outside), though music gear adapters often use Center-Negative.
Protection Features: Over-Voltage Protection (OVP), Over-Current Protection (OCP), and Short Circuit Protection (SCP).