The two piece spring and hook allows you to fit the bobbin inside the spring hook around a bobbin.

The spring is thus secured to the bobbin via the spring making it tamper resistant. Once installed its difficult to take off, especially when the fence is on. 

The Stainless Steel Hook and Spring is ideal for using with Stainless Wire Types. (Like metals no electrolysis)

Where Galv or Aluminum wire is used the Nylon plastic insert is used. (No electrolysis)

Maintains tension on fences through temperature changes.

For wires 1-1,2mm

The two piece spring and hook allows you to fit the bobbin inside the spring hook around a bobbin.

The spring is thus secured to the bobbin via the spring making it tamper resistant. Once installed its difficult to take off, especially when the fence is on. 

The Stainless Steel Hook and Spring is ideal for using with Stainless Wire Types. (Like metals no electrolysis)

Where Galv or Aluminum wire is used the Nylon plastic insert is used. (No electrolysis)

Maintains tension on fences through temperature changes.

For wires 1-1,2mm