The plug completely sits inside the unit with the cable being fed through an access hole.The small unit is suitable for a variety of electrical connections up to 40 mm diameter, with a locking mechanism that can accommodate up to 4 safety padlocks.The large unit is suitable for standard and larger electrical plugs, including 3 phase connectors.Plug lockout prevents electrical plugs from being inserted into a wall outlet.Small 110V plug lockout : 80 H x 44 D x 42 W mm with " diameter hole for cable.Large 220V 500V plug lockout : 155 H x 86 D x 84 W mm with 8.5 to 19 diameter holes for cabl