or, rather than measuring, they looked at a spec sheet that said 1", which for the TF series would be the heavy duty item, if the ends fit, it should do OK if yer not doing a bunch of rock crawling
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics