This is a glass slide from the Lapp factory showing a 5-part porcelain insulator. One of the slides was dated 1923, so feel certain this slide was from the 1920's. The only other 5-part insulator was M-5000 shown in the circa 1920 Pittsburg catalog. The Lapp style has been assigned M-5001. It appears to be similar to M-4440 (15 - 13 - 12 - 10 x 14.5) with another 15" skirt on top. The height may be as much as 18" by ratioing the skirt diameters in order to estimate the height. I estimate the dimensions on it will be about 15 - 15 - 13 - 12 - 10 x 18. Weight estimate?? We now know a 5-part insulator was actually made -- not just a Pittsburg pipe dream. Looks like a good reason to order suspensions.