Military Morse Code Keyer Practice Key with Oscillator Telegraph Key NOS

For sale is one (1 pcs) vintage, NOS (New Old Stock) MORSE CODE KEYER - PRACTICE OSCILLATOR WITH KEY, extremely hi quality product from late 70s, early 80s with earphone and line cable for Morse telegraph network

• Frequency 300-2500Hz (adjustable)
• Output power 25mW at 800Hz
• Built-in loudspeaker
• Earphone 3.5mm jack for headphones
• Small ear headphone included
• Dimensions: 130x70x55mm
• Weight: 380gr
• Two or more of these keys could be connected in network through line connections (cable included)
• It runs on 2 AA 1.5V bateries
• Non-skid heavy  base -- it stays put on table and doesn't move around while you're sending!
• When the volume button is in off position, you can connect it to any transmitter and use it for QSO
• Spring force (Arm tension): 0-600gr adjustable
• Contact spacing 0-1mm adjustable (1-9 on scale, where 1 is 0.1mm and 9 is 0.9mm)