The Low Voltage cap will add ambiance, safety and security to your yard. Installing low voltage lighting on your fencing or railing is safe and very simple to do. This cap fits externally on a true 5” x 5” post or 4" x 4" Post. The total height is 3.625”.  You will need to purchase a transformer at your local home and garden store (size of transformer depends on how many lights you purchase - i.e. if you purchase 20 caps (size of transformer depends on how many lights you purchase - i.e. if you purchase 20 caps (20*4watts = 80 watts - so you would need a transformer rated above 80 watts). Use standard 12 gauge low voltage wire which can be run inside our fence rails.