These MC4 type branch connectors allow two PV strings to be connected together in parallel.
They are sold in male and female pairs.
Note that if you use 2 sets of branch connectors to connect more than 2 PV strings together then you need to be careful not to exceed a total of 30 amps and a 15A string fuse may be needed
Note: if wiring your own system in NZ, you can do so for voltages up to 120 VDC (ELV) if you have suitable knowledge and experience. For LV systems (>120 VDC) this is prescribed electrical work and it must be done by a licenced electrician.