From Amazon
Adastra | Megaphone Bullhorn Loud Speaker with Siren & Carry Strap | 600 Metre Range with Siren & Volume Control
Farnell
Adastra L10 Megaphone 10W With Siren
CommsAndSound
Adastra L10 Megaphone 10w With Siren
Digi Spot
ADASTRA L10 Megaphone 10W With Siren