Hi , 

Thank you for providing the images! 

In regards to the rubber caps themselves, the rubber caps are weather resistant to an extent, but they do not carry their own formal IP rating. The plugs themselves (the electrical pins) have a high ingress protection rating like IP54 or IP65 when plugged into a vehicle or charging station, however the rubber caps only offer basic protection against dust and water spray when the cable is not in use. 

Looking at the pictures, it seems the water would have been seating on the plugs when not charging, when the cable is not in active charging, the water does not evaporate, hence why corrosion happens. 

Please note that water damage is not covered under warranty, however the plugs can be repaired by purchasing our repair services: https://evcables.com/products/cable-repair?_pos=1&_psq=cable+repair&_ss=e&_v=1.0

If you'd like to opt for the repair service, please respond to this email as we will need to RMA the cable, the customer would also have to ship the cable back to us (a return label can be purchased via our website too https://evcables.com/products/return-shipping?_pos=1&_psq=return&_ss=e&_v=1.0). The fee for shipping the cable back to the customer after repair is already included on the total on the repair fee on the first link provided.