4.0 mm. gold-plated power connector. *Dad*.

Connector at all times ... One of the most widespread and popular power connectors Modelling.

Maximum operating current - 80A.
 
Can and more - losing just a little increase. And will bask.
 
Contact resistance - 2-4 milliohms. Depending on the degree of wear.
 
These connectors are successfully used in all classes of ECO in MONO1,2, in HYDRO 1,2. The class F1E.
 
Weight plug 4.0 mm - 1.6 grams
The outer diameter of 5.0 mm
The length of the connector - 20 mm.
 
Attention - here you can buy *Dad* connector only.

Mom's here.

If you need a pair: socket/plug, then you make the required number of separate sockets, you need a number of plugs.