SP-2W is for 8 gauge wire and fits both standard (1/4 inch) and wide (5/16) inch binding posts.
Overall width: 0.575 inches (14.6 mm)

SP-10 is for 10-12 gauge wire and fits both standard (1/4 inch) and wide (5/16 inch) binding posts.
Overall width: 0.525 inches (13.4 mm)

SP-14 is for 14-16 gauge wire and fits both standard (1/4 inch) and wide (5/16 inch) binding posts.
Overall width: 0.525 inches (13.4 mm)

BSP is a mini-spade for the screw terminals on vintage amps & speakers. Fits 10-14 gauge wire.
Overall width: 0.313 inches (8 mm)

All DH labs spade connectors are made from pure copper.