Add-A-Shroud® devices allow conversion of existing 20 A and 30 A 3 - 5 wire Hubbell Insulgrip® Twist-Lock® devices to a Safety-Shroud® Twist-Lock® plug The Safety-Shroud® Twist-Lock® plug permits engagement with the Hubbell mechanical interlock enclosure which virtually prevents make and break under load These devices provide a convenient and cost-effective way to convert existing Hubbell Insulgrip® Twist-Lock® plugs to Safety-Shroud® Twist-Lock® plugs