Booster amplifier for 2m (144MHz). Previously, it was fixed and used to increase the output of handy machines. I think that it was about 30w output with 3w input.It is recommended to use 1-2w for continuous use. It is unconfirmed because there is no environment that can test transmission and reception at present. S : New/Unused(Open box) A : Mint -Almost Unused B : Excellent - Beautiful item for used C : Very Good -A few scratches but looks good D : Good -Just fine E : Imperfect -There may be a problem or shows sign of age F : For parts or not working, untested, only powered on, needed maintenance, etc.. The EMS is the safest and quickest way of Japan Post. Due to the influence of virus. Our products are 100% Authentic. We are really glad to have a deal with people all over the world. International Buyers - Please Note.