There are 3 product entries in this website that use the same three photos on each. There are two male sockets that are "socles de prise saillie" and one female socket of the type 'socle de prise tableau droit' . They are all socket outlets, but the one being sold in this entry in the website is a male one.
There are other entries in the same website that have four images on their page but the item being sold is only in two of the four photos eg
https://www.vdm-reya.com/001486-gt-multigrip-prolongateur-fe... and
https://www.vdm-reya.com/002741-gt-multigrip-prolongateur-fe... On other websites, where SOCL is used, it seems to be where there's not enough space to fit in the whole word 'SOCLE'. I can't find any other mentions of '+SOCL' anywhere else other than here
https://ouest-accastillage.com/prises-etanche-bateau-fiche-m... and this is exactly the same as the big photo in your reference. There are, however, no other photos along with this new reference so I don't think it can mean that it comes with another socket.
peer agreement (net): +3