The PLI-DIN audio line isolator was developed for the special requirements of the installation market. Two high-quality isolating transformers are enclosed in a standard, 70-mm wide top hat rail case. The connections are made using so-called "Phoenix" contacts. There are two different versions of the PLI-DIN: LO-Z with a nominal impedance of 600 : 600 ? is optimised for the balancing and electrical isolation of outputs, while HI-Z with 10 k : 10 k? is suitable for adaptation of line inputs.