Briselec they are 3P elements.
One small change is the 6mm element cables will have to now be upgraded to 16mm to allow for the grouping factor in the trunking.
Those element cables are also NOT V105 ( high temp) rated and they terminate straight onto the elements. But wait, theres more...... The elements aren't supported at both ends and they sag and rub against each other. But wait, theres more...... The water feed into the tank points straight into the elements with no baffle. When the pump switches on you can hear the elements rattling against each other.