The order arrived on time and well packaged. I realised, quite quickly, that the most important point to take into consideration was the datum point. I made that to be centered about 1 and 1/2 inches above the fire reveal. Most measurements are taken from this point. There are four support pin holes drilled into the rear of the beam and these, on my 6 foot curved beam, are 18 inches apart. They are also 2 and a half inches from the top of the beam. Using a 4' level I marked the hole centres and triple measured the dimensions. I also made sure that the markings were done, making a half inch +. I drilled with a 5mm masonary bit first, to really centre the holes, then went up to the 10mm. (Try and make sure that you drill into the wall at 90 degree and make sure that you have drilled deep enough to accept the pins!) ) Use the level again, across the pins once they are driven in, to make sure that the pins are level. (\you may be able to adjust the position of the pins slightly.Measure 18 inches from the centre of each pin to the adjacent pin; adjustment is possible using a small hammer. When you drive the beam onto the pins be aware that you have a small chamfer on the pin to facilitate fitment. It may seem a daunting task to start with but, providing that your drill measurements are correct, all should be well. Good luck. I would buy from this firm again. Go for it.