This is an ACR RT-10 survival radio. It was a standard issue item to pilots of all branches of service during the Vietnam war. This particular RT-10 was given to me this
ACR SR103, P/N: 2727 SURVIVAL RADIO C/W LITHIUM BATTERY, MULTI-CHANNEL
ACR VHF/GMDSS Survival Radio
ACR - SR203 VHF Handheld Survival Radio
ACR Rapid Charger Kit f/SR203 [2815] — CE Marine Electronics
ACR VHF GMDSS Radio
Rechargeable Replacement Battery for ACR SR203 VHF Handheld Survival R – Life Raft and Survival Equipment, Inc.