If you mean for attaching to a column I don't know, but there are a lot of good compression type connectors for making up the grid. Just ask the lug people like Ilsco and T&B.
They may of been referring to a HyGround system - compression, from Burndy. It used to be Burndy - compression vs Cadweld - exothermic, but now Calweld makes compression connectors and Burndy makes exothermic, so less fun at trade shows to ask which is better.