This Soft Key Kit, safely acts as an amplifier interface to your modern transceiver to the Drake L-4 or L-4B Linear Amplifier. This unit is mounted inside the amplifier and transforms the 24-27VDC key closure to approximately 1 VDC at 1.5 mA. Without it, you run the risk of severely damaging the keying circuit in your transceiver. This is an un built kit and is very easy to assemble with step by step instructions. This is a great addition to a great amplifier! For Ebay Customers: Due to recent rule changes and ebay's increased effort to prevent sellers from communicating with their customers outside the ebay message system, I am no longer permitted to list my email address or my web site in my ebay listings. If you have any questions about this item or DISCOUNTS for this item, please click on the link below to go to my ebay "ME" page where all my contact information is listed.Please CLICK HERE for "ABOUT ME" Information ! Good Communication and Customer satisfaction is always our number one concern so feel free to contact me DIRECT via email or telephone. (Anytime before 9:00 PM CST for Phone Calls)If you do purchase an ebay item from me and for some reason are not satisfied or have questions, PLEASE contact me right away and I will take care of it to your satisfaction, (rather than leaving negative or neutral feedback before I am made aware of a problem). I sell hundreds of pieces of used and new gear and it is possible I could miss something or make an occasional mistake, but I will always work to make sure you will be satisfied or I will refund your full payment including the shipping cost, so there is no risk you will be stuck with something that you do not want. I know there are many sellers that do not much care about your satisfaction but I am not one of them! Please consider this before you bid on my items and before leaving any negative or neutral feedback.International sales welcome! If PAYPAL Payments that total over $250.00 USD are from an unverified account or an account outside the USA, The item MUST be shipped via USPS Express Mail, UPS, or Fed-Ex, with a signature upon delivery. (Not Priority Mail) NOTE:Please Click the "More Auctions" Logo below, to see more related items!Please CLICK HERE for "ABOUT ME" Information !