I bought the 4100 saw without the digital readout and wanted to add this feature, so when it became available, I purchased it. It is a very well constructed piece of equipment as most Bosch stuff is. The assembly was simple and the instructions were clear and it was easy to attach to the saw. The readout is large enough to see easily and bright enough for work outside. Easy to zero and then set your rip dimension. It works really well and allows a reading for a wide rip with the sliding table feature on the 4100 and gives very accurate readings (I trust it more than my ruler now!)
br /The only irritation I have is the auto shutoff seems to be too fast if you are making multiple settings. You just have to hit the on/off button and it goes back to the set reading, but a little aggravating. I need to measure the time and see what it is.
br /All-in-all a very good investment and first quality!

Went together easily and seems to work well. To date, I haven't checked to see if the measurements are accurate.