Armour™ Ring – A simple conical collar which is hammered over any standard bolt or nut, rendering it tamper resistant.  This security fastener has the advantage of not being governed by torque and can be applied to existing fasteners.  Another advantage of using the Armour Ring is that it leaves a smooth cover to existing fixings.  Armour Rings are suitable for any British standard or DIN standard hexagon bolts & nuts, including hex head coach screws.  No specialist tools required.  Uses standard hammer.  Manufactured in bright zinc plated steel and stainless steel.  Cannot be easily removed.  Home Office approved.