Great earpiece. Especially for the price. We also use the part number "RLN5318A TWD" and actually like those a lot better. Two Way Direct has those for $35. Definitely recommend getting that version.
PMLN4606A: The PMLN4606A TWD is Our Replacement for the Motorola Original Black Split Wire Surveillance Kit.
Designed specifically with budget in mind, this split wire surveillance kit offers fantastic audio quality with reliable components and is the ideal accessory solution when low cost is the main issue.