This is a very clever utility prop which allows you to present many different tricks, but it is also a useful device. Basically, the glass is filled with liquid in front of an audience; then a lit candle is pushed through the glass and the candle stays alight!
Or a borrowed ring/coin is dropped into the full glass only to reappear in a nearby box! (Please note: the silk is for illustration only.)Sturdily made in polycarbonate.