Barrier seals are very widely used trailer seals because they are cost effective and will solve all the security problems in almost all the cases. Different types of barrier seals are discussed in this article. The Alulock Cable Seal is a simple to apply high security seal which offers an all metal alternative to the plastic seals. Fast grip cable seals are available with varying cable diameters to accommodate all applications. They are virtually impossible to replicate and are extremely’ Tamper Evident’. Company identification and security numbers remain secure inside the high tech plastic case which is then ultrasonically welded for ‘Total Security’. High security bolt seal is an ISO/DIS 17712 compliant High security bolt seal with seal print and numbers encapsulated by a polycarbonate plastic cover. The barrel and pin coating is made of hard and durable plastic to reveal evidence of tampering attempts.