Sollos 100W Black Coated Lighting Transformer with Photocell Timer (997012)Corrosion resistant stainless steel finish (TR12SS) Black polycarbonate finish (TR12PC) An integrated photocell and timer enable light fixtures to function manually, automatically, or via a timer Automatic functionality activates lights at dusk and deactivates them at dawn TR12PC Timer activates lights at dusk and turns them off 4 hours, 6 hours, or 8 hours later. TR12SS Timer activates lights at dusk and turns them off between 1 to 9 hours after dusk