التَّحِيَّاتُ لِلَّهِ وَالصَّلَوَاتُ وَالطَّيِّبَاتُ، السَّلَامُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللَّهِ وَبَرَكَاتُهُ، السَّلَامُ عَلَيْنَا وَعَلَى عِبَادِ اللَّهِ الصَّالِحِينَ، أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ
Transliteration
At-tahiyyatu lillahi was-salawatu wat-tayyibat, as-salamu 'alayka ayyuhan-nabiyyu wa rahmatullahi wa barakatuh, as-salamu 'alayna wa 'ala 'ibadillahis-salihin, ashhadu an la ilaha illallahu wa ashhadu anna Muhammadan 'abduhu wa rasuluh
English meaning
All compliments, prayers and pure words are due to Allah. Peace be upon you, O Prophet, and the mercy of Allah and His blessings. Peace be upon us and upon the righteous servants of Allah. I bear witness that there is no deity except Allah and that Muhammad is His servant and Messenger.
When is it recited?
Recited while sitting at the end of every second and fourth rak'ah.
Source
Bukhari, Adhan 148, 831; Muslim, Salat 60, 402