A downhole tool that is located and set to isolate the lower part of the wellbore. Bridge plugs may be permanent or retrievable, enabling the lower wellbore to be permanently sealed from production or temporarily isolated from a treatment conducted on an upper zone. Bridge plugs are typically manufactured from a number of materials that each have their own applicable benefits and disadvantages. For instance, bridge plugs made out of composite materials are often used in high-pressure applications because they are able to withstand pressures of 18,000-20,000 psi (124. On the other hand, their permanent use tends to lend itself to slippage over time due to the lack of bonding between the composite materials and the materials inside the wellbore. Bridge plugs fabricated out of cast iron or another metal may be perfect for long-term or even permanent applications, however, they don’t adhere very well in high-pressure situations.