Similar in design to the two piece celluloid trumpets this telescopic aid is slightly older, dating to the end of the 19th century.
I cannot be sure what the underlying base metal is because it has been completely and rather skillfully leather lined. Although there is some brass visible at the join, it is actually quite light and I suspect it is made from tin. It is rare to find the leather in such superb condition throughout. The earpiece is made from ivory and is fixed.