The Nittan 2KH-4T was a popular conventional optical smoke detector.  It was however made obsolete several years ago.

Nittan 2KH-4T Conventional Optical Smoke Detector

If you're looking for a replacement for the Nittan 2KH-4T then the Nittan ST-P-OM detector can be used as a direct replacement.

If you're interested in these products you may also be interested in our wireless fire alarm systems