For balancing and isolation of line-level outputs from mixers, equalizers, crossovers, and other equipment. 1/4" (6.35mm) T/R/S and female XLR-type input (with parallel 1/4" and male XLR-type output). 1/4" T/R/S and male XLR-type transformer isolated outputs with ground lift switch. Uses Pro Co LOT-1 transformer (600Ω 1:1).