The Model #4 Cast Iron Latch Family are the most common 4 Series latches. These are often used on equipment where a higher general operating pressures can exist such as a blast panel on a dust collector. The #4 Cast Iron Model family can be configured with or without handles two different types of handles, and mate with 3 different strike options for different mounting needs. Note: The 84 series is more economical modernised version of the Model #4 Cast Iron Family of products, we recomend this upgrade moving forward. The 94 series offers the maximum corrosion resistance.