Flame detector MZ770S for R20 and R30 with 2-fold extension (L=220 mm), e.g. for Giersch type series R20 and R30 such as R20(-V)(-L), R20(-L)AE, R20-ZS-L, R20(-V)(-L)-Bl Nox, R20-Z-L-Bl Nox, R30-AE, R30-Z-L, R30-Z-L-Bl Nox, R30.3-Z-L-LN. Ref. no. 47-90-21037.