RTS telex kp412lk-e with lever key intercom panel

From RTS below

The RTS KP 612/KP 412 keypanel fits in a standard 19” rack and is one (1) rack-unit high. It has 12 keys, each key consisting of one (1) listen button and one (1) talk button. Ten keys are used for intercom talk and listen and two (2) keys are for callwaiting response.

In addition, there are two (2) encoders. One (1) encoder is used for Headset, Microphone, Auxiliary Input, and Matrix In
volume adjustment. The other encoder knob is used for menu selection. The KP 612/KP 412 keypanel has a standard
numerical keypad with four (4) extra keys: Mic Mute, User Assignable, Page Up, and Page Down.

The KP 612 has a 6-character display panel and the KP 412 has a 4-character display panel. The KP 612/KP 412 keypanels have added significant new features such as digital signal processing (DSP). The KP 612/KP 412 keypanels also offer a custom design LCD display with support for 16 x 16 Kanji, Katakana, Hiragana, and English characters.

The KP 612/KP 412 keypanels are made of pressed aluminum/metal and feature state of the art audio processors and drivers.