Barrier Terminal Blocks with Spade Lugs - TruConnect 21-3073, These 4-way screw to screw terminal blocks are of excellent quality and competitively priced. The block\'s rugged construction of high impact material will protect the filter elements during installation and field service. Typical applications include filtering power supplies in telecommunications equipment, metering, industrial controls, instrumentation and EDP equipment. TruConnect 4 Way Screw to Screw Barrier Terminal Block