Redlam Mark 1 panic bolt - Manufactured from cast iron aluminium. Redlam panic bolts are economical solution to the problem of providing reliable security for internal emergency exits. Designed for emergency exit single doors. Breaking the CeramtubeTM results in the bolt sliding back automatically and unlocking the door. CeramtubeTM - Replacement cartridges for both MK1 and MK2 Redlam panic bolts. Designed to produce no sharp edges when smashed.