OLT Series Trogamid optical liquid level switches feature solid state technology with no moving parts. They have a miniature size and are easy to install. They are available in TTL compatible or transistor output versions, with output current options of 10mA, 250mA, or 500mA. The switches are housed in Trogamid material, which provides high media compatibility and fast response. Electrical connections are available in both 3-wire and 4-wire versions.