The underblanket or liner can be attached to most of the Horseware blankets with a velcro-loop attachment around the neck area nad clips in the back corner of the outer blanket.  The attachments prevent the liner from slipping under the outer blanket.  It is a simple system which gives your blanket superior insulation properties without the expense or inconvenience of using two seperate blankets.

 

This allows you to have an extra relatively inexpensive liner so that it can be washed in a domestic washing machine without having to wash the outer part which can be detrimental to the outer shell.