It's a pre-injection swab used to cleanse the skin before taking bloods or giving an injection made by Seton Healthcare Group Plc
An example of which can be found here
http://www.wms.co.uk/Sterets_Pre-Injection_Swabs.html?A=1&GID=10038&SSID=3159&SID=999
ALSO:
STERET is an experimental band from Minnesota.
http://www.facebook.com/?ref=home#/pages/STERET/188447624832?ref=ts
http://www.myspace.com/STERET
http://www.discogs.com/artist/STERET