Well it a Simple ' Sliver Ball with Liquid in it that 'Freezes once put in the Freezer and you remove it and Place it in Chinese 'Plastic Case to Hold it as you Screw it in Place and Roll.' It on your Sore Body 'Part...Fills pretty Good and Thumbs the Aching Area because it is Sore & Aching...I purchased $$ an 'Extra 'One as Advertised and ' ONLY RECIVED 1 SILVER BALL....WITH NO.' ATTACHMENTS....I.Was'nt told that...I thought I was going to get another "Complete 'Set...But didn't....'Only have 1 ' Silver Ball.....I need that ATTACHMENTS for my Wife....How do I get it ? ..Not a Bad Product....Feels Great..