The ICOM SP-40 mono earphone has a 39-inch wire that ends with a 2 conductor 1/8" (3.5mm) plug. The earphone comes with a removable soft earbud.
A replacement earbud of the same size is included. Additionally, a smaller earbud is also included.
This is for the ICOM IC-Sat100
https://www.satmodo.com/product/icoms-ic-sat100-land-mobile-radio-lmr/