Double Servants?

My 10X great grandfather, Simon Cooper from Peasmarsh, Sussex left a most interesting Will in 1626.
He left ‘Double Servants’ to his son Henry and Daughter Margaret. These Double Servants were most likely ‘indentured servants rather than ones who might have been enslaved.
This proved to be an interesting find, where when one ‘shakes’ the family tree, you never know what will fall out! Sincerely Trevor