An Essex shoe company has developed a bombproof boot which has proved so successful it is being used by armed response units.
A stun grenade was taped to the side of the boot and ignited
The footwear, from Hi-tec in Rochford, is used by Herts police who tested the boot by strapping a stun grenade to it.
The Magnum Elite boot caused "minor damage" by the controlled explosion.
The force took steps to change their supplied boots for the units after two officers suffered severe injuries to their feet and ankles during training.
Nick Barnes, head of procurement at Herts Constabulary, said: "The failure of the supplied boots caused two officers to suffer severe injuries to their feet and ankles.
"These injuries occurred during training where stun grenades were deployed.
"In both cases the grenades went off beside the boots.
"The blast in both cases blew holes in the sides of the boots causing injury to the officers' feet and ankles."
After these injuries Hertfordshire police stopped all ARV personnel from wearing this specific boot.
It was decided to trial four boots that met the criteria required for ARV work and conduct controlled explosions on them.
All tests were formulated to replicate the situations in which the accidents occurred.
A 'NICO 9 bang' stun grenade was taped to the side of each boot and then electronically ignited.
The Magnum Elite 8" Leather was the overall winner with minimal damage.
Armed Response Vehicles (ARV) are crewed by uniformed officers who have been trained to stabilise and control armed incidents, stop and search suspects and to search premises for armed suspects.