Restraint apparatus and methods for securing items are disclosed. The assembly includes a housing having a bottom configured for supporting the housing on a surface. A message received at an interface connected to a trusted source has the port address associated with that message mapped to a predefined port address by a firewall computer, before being passed to a server computer or other system resource. Interactive tools for slicing multi-dimensional regions and drawing superimposed projections in 3-D space are provided. A method for producing a tire pressure monitoring unit is also disclosed.