The very interesting feature is the "hammer lacquer" finish. Not typical on today equipment
Inside the mechanism is very conventional and heavy duty. The quality "shows".
This side shot is showing the simple and serviceable mechanism. The range of adjustment is very good. From "foot pressure" to "feather touch".
I have owned the Czech Army key for a few years now. Also purchased on eBay for at the time was very economical price. I remember training on this key in the army more than forty five years ago. I still think it is one of the best hand keys I've ever used. The key is excessively over engineered and of sturdily built .
The classic Bakelite box and very unusual arm and hinge/rocker. Very comfortable finger piece.
The mechanism inside is complicated and atypical of most hand keys. Normal adjustments for travel and pressure. Spring looks big, but the way it is positioned makes the movement effortless.
By moving the arm up you switch from transmit to receive.
I don't even remember how long ago I've used a straight key in a QSO. My technique must be terrible (that reminds me to do some practise). I find that with paddle I can send much better quality CW than I could ever send with the "pump". Still it is nice to own several straight keys.