ST-2 is identical to ST-1, but with chrome base
The underside of the ST-2 has 3 female and male disconnect terminals for ground and each of the DIT and DAH connections. HF transceivers equipped with either a 3.5mm (1/8") or 1/4" KEY input jack can be hooked right up with the EZ-1 kit. The EZ-1 has a 3 wire cable with the correct female terminals on one end for the ST-1 and ST-2, on the other end a 3.5mm connector with a 1/4" adapter included. No soldering. Plug the terminals onto the bottom of the key, plug the other end into the KEY jack on your HF rig.