Beer can structure

A sealed can structure including a cylindrical wall member, end wall members located substantially at each end of said cylindrical wall member and sealing said can, a potable liquid located within the can structure and intended in its potable condition to exert at least a predetermined gaseous pressure of about 12 psi internally of said can, a tab formed integral with but separable from one of said end wall members, a pull ring having a substantially circular opening and joined to said tab for separating said tab from said one end wall member and gaining access to the contents of said can, and integrally-formed indicator means in said one end wall member, said indicator means being substantially disc-like and being located at least partially within the circular opening in said pull ring, said indicator means being constructed to assume one position relative to the remainder of said end wall member when said internal pressure exceeds said predetermined pressure of about 12 psi and to assume a second position relative to the remainder of said one end wall when said internal gaseous pressure is below said predetermined pressure of about 12 psi through opening of said can or through leakage of gas pressure from an unopened can, said second position being usually and tactilely different from said first position, whereby external examination of said can in the immediate vicinity of the tab and pull-ring for said can reveals whether or not said internal pressure has fallen below said predetermined value of about 12 psi and hence whether or not pressure leakage has occurred.