... neutral weather resistant silicone sealant is mainly for sealing in glass, metal(except copper), concrete, marble, tile ,etc M-820 neutral ... curtain wall such as glass, aluminum and ceramics; Sealing for marble, granite , concrete, brick and tile, metal panel; Other uses. ... manufacture dateF .CAUTIONSDont use for the alkaline materials such as marble, granite etc; Dont use for the hide and semi-hide ...