Laufen 8.9343.8 replacement
Usually found in these popular Laufen toilet cisterns:
Arolla,
Design, Form, Gallery, Pro, LB3, Living, Mimo, Mobello, Moderna,
Mylife, Object, Palace, Palomba, Radial, Il Bango Alessi, Swing,
Universal & Vienna
Your old button my have a silver square, not blue. This is a direct replacement