Either research where to buy, or make in-hear headset with 4P4C plug for business phone.
Research where to buy one simple in ear headset. Nothing fancy, the type you find often prepacked with mobile phones: two earplugs, and one mic where the two earphone cables run together. I searched the internet up and down and could not find anything, except some outdated, overpriced Plantronics items, which also didn’t have the mic attached the way I wanted. If you think you found something for less than 30$ and ships to Ireland, send me a picture (if you want modify it so I cannot reverse search it) and place your bid. Quick disconnect plug would be ok too. I am only paying for successful research results. Alternatively, you can ofc just bid on selling me one that you own or you can buy.
Create one yourself. You bid (rate * hours) on the total costs incl. shipping and handling to Ireland. Sending via letter should be ok. No cheap adapter solution. The sound quality of the whole product needs to be DECENT and NOT COMPROMISED (low volume, distorted, noisy) in any way. If you want to bid, send me pic of the headset you intend to use (plug doesn’t need to be included in picture).
Please include hourly rate and hours in your bid, and specify what you are betting on (research, sell, create).