Steam power makes it go eenk-oonk-eenk (pardon the technical terminology). This links up to other Steam blocks and can conduct steam power.
Steam Bellows price in Growtopia: sells for about 10/WL (median of 5 offers from community Discords, past 30 days). Live price chart and the latest buy and sell offers.
Recently sold at: INIDUREN, 3OHI, QALDEN, MORNYE