Alternatives:
CCGR L
Cardas CCGR-L Long billet Copper posts, Rhodium over Silver plate. Billet Copper nut, Gold plate. Glass filled nylon insulator.
Sold as a pair (two posts), includes an insulator plate, plated hex nuts, and black washers. (as in pictures)
It can receive 4mm banana plugs through the top and can receive a spade from the side with an opening of 6mm or more. Internally the posts are solderable.
CCBP L
Cardas Colver binding post, long billet high purity copper posts. Billet Copper nut. Glass filled nylon insulator. Can receive 4mm banana from the top and spades with an opening wider than 6mm from the side. Solderable. Sold as individual pairs - 1 x nylon insulator, 2 x nylon washers, 2 posts and 2 nuts. Please note there are 2 pairs shown in the picture.