They were utterly useless whan I needed a new USB transmitter for a mouse, tough luck buy a new mouse was the attitude
same here brought a mx3200 mouse and keyboard broke the wireless transmiter and it was just a case of tough luck buy a new one. i think it was around £80 at the time and couldnt afford a new set
so brought a cheapo logitech wireless mouse and kb as a replacement. and out of curiosity tried to sync the mx3200 and ill be a ***** ******* **** weasel it worked still using it today. well the wife is, result