It is unlocked (originally Vodafone) and tested working on O2, Vodafone and EE networks as shown in picture 2. This 2G phone will not work with Three Network sims as they no longer provide a 2G signal on their network.

Brand: Sony Ericsson
Screen Size: 2 in
Network: Unlocked
Model: W580i
Connectivity: 2G, Bluetooth
Memory Card Type: Memory Stick Micro (M2)
Style: Slider
Storage Capacity: 15 MB
Lock Status: Network Unlocked
Model Number: W580i
SIM Card Slot: Single SIM
Colour: White