This looks a bit safer if you are doing them on the regular.
http://www.ebay.com/itm/372738206695?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=372738206695&targetid=1068323860310&device=c&mktype=pla&googleloc=9014929&poi=&campaignid=11612431353&mkgroupid=114626995633&rlsatarget=pla-1068323860310&abcId=9300456&merchantid=7940664&gclid=CjwKCAjwvMqDBhB8EiwA2iSmPCw17gHXVoSIMtCBP2QLZdDkjucs76l3-1JEeTuVwACOHz4IcFReLBoCDIIQAvD_BwE