Extreme Noise Earpiece Adapter Kit, Noise Reduction Rating = 24dB. This is the replacement for the NTN8370.
Includes 2 foam earplugs for loud environments and provides 24dB of noise reduction

(CT150, CT250 & CT450 - use with RLN4895, HMN9754, HMN9752, HMN9727 & RLN4894)
(HT750, HT1250, HT1250-LS, HT1250-LS+ & HT1550-XLS - for use with AARMN4021, AARMN4022, AARMN4028, AARMN4029, ENMN4014 & ENMN4017)
(EX500 & EX600-XLS - requires PMLN4455 if used with BDN6667, BDN6729, BDN6668 & BDN6730 earpieces - Intrinsically Safe (FM))

Motorola
Item: RLN6230
This item works with the following Two-Way Radio Models:
Motorola CP150
Motorola CP200
Motorola SP50
Motorola PR400
Motorola P1225LS
Motorola P1225
Motorola CT150
Motorola CT250
Motorola CT450
Motorola EX500
Motorola EX600XLS
Motorola HT750
Motorola HT1250
Motorola HT1250LS
Motorola CT450LS
Motorola GP300
Motorola GP350
Motorola P110
Motorola CP110
Motorola EX560