A Playaboule product
This 52mm dia (2 1/16") polished chrome steel pallino weighs 10 oz (280 gm) 3/4 lb so will not get bounced off a court as easily as the standard phenolic/plastic pallinas.
Note: These are hard chrome plated steel balls. On abrasive surfaces the chrome will wear off, first exposing the copper bonding and then the steel ball underneath. No problem, they are just not as shiny as new.