It fit and worked perfect for about 6 weeks. Then I saw a small spark at the switch override and it was done.Fortunately it fused in the on position. I am able to control it with the breaker until I can get a replacement.Unfortunately my return window is closed...Product was used for aerator pump on septic system.I was thrilled to find this timer to replace the failed one (it would not turn off at night) in my pool panel as the mounting is custom made for this device. As others noted the actual SPDT load switch on the new unit has the Normally Open and Normally Closed contacts reversed as compared to the original switch. Funny thing is that the printed diagram's on both units is the same and I'd say that the old unit was actually wrong.In any case it was a 5min swap to fix my panel and sort the connectors. The original unit lasted over 15years so hopefully this one will go the same distance.PerfectThis clock features the manual over-ride toggle on its face. This photo from the supplier does not depict that feature. The override feature controls; on, auto, and off modes. The clock operates in the auto mode. I took a chance on it being the item I needed and was correct due to the correct description. All Intermatic FM clocks by 1000 bulbs have the identical picture even though they are different.This clock is also known as a Grasslin brand clock. Intermatic acquired them a while ago but the clocks still have the Grasslin brand name on the face.This clock is used to run my pool pump. I could not find this clock at my local pool supply house. They said they would order it for me for $139.00. I decided to check Amazon but could not find the correct clock. I happened to notice that the Amazon supplier used the same photo on each picture. After much resurch I found that Grasslin was acquired by IM so I went to the IM website to gain a part number match.The supplier shipped the clock to me very quickly and I could not believe I saved $100.00 for the exact same part I needed. Other than the minor photo mix up I am extremely satisfied with the service I receivedProduct arrived earlier than expected. Worked Great would order again if need be!The reason that I selected this product was I currently own an electronic timer. When I use the electronic timer it is 1) difficult to set up with the current time and the operating intervals; 2) even though it has a battery backup, it loses the current time setting when a power outage occurs; 3) the button controls are unresponsive at times when trying to set up the timer; 4) various other problems with the operation of the device. Although I have not installed the intermatic non-electronic timer yet, I can see that the interval setting are very simple as well as the current time setting. This timer should simplify and greatly improve my ability to control the swimming pool filter that I will use it for. One strike against electronic gadgetry.Very nice product that was an exact replacement for my Aquasafe aerobic septic timer. Easy to install and setup. Remember to pull the breaker and verify there is no power supply when replacing!Timer was perfect for the repair needed to the hot tub. It was an exact fit Thank you for the quick delivery.