These fit a 3" PVC pipe with no liner.  YOu get all 3.  If you need the center hole a different size let me know.  Also I can make some for the Soapers choice silacone molds that are 2.75"  Just make sure to tell me its for the smaller molds.  A all thread rod will fit in the center it you do not want to use strings.  You will purchase 6/32" to 1/4".  

Set of 3 Different Disc Pull Through soap tool