It a pump with a tube fitted and an airstone attached, good for aearation if your filter dosn't have a good surface flow, plus good when you have to use med, as meds take the 02 out of the water, and you need alot of aeration in a cycling tank.
http
/www.aquatics-online.co.uk/Z054161.asp
http
/www.aquatics-online.co.uk/Z058163.asp
http
/www.aquatics-online.co.uk/Z054161.asphttp
/www.aquatics-online.co.uk/Z058163.asp
