Here are pictures of the three different major types of Toggles. The different Toggles shown from left to right are a) an A-3 Serial Toggle, b) a D-1 Standard Toggle and c) a F-4 Chrome Toggle. At first glance they all appear similar, but they are different in a few ways. First, look at the micrometer adjuster. The leftmost Serial Toggle has a "Red Dot" position indicator and it's maximum position setting is "5". The middle Standard Toggle also has a "Red Dot" position indicator, however it's maximum position setting is "9". The rightmost Chrome Toggle has a "Black Spring" indicator which has two function: to indicate the position and to provide resistance and tactile feedback at each setting. Next, look at the heads. The blade trays are different on each type. The leftmost Serial Toggle adjusts the blade by applying pressure to the blade in four (4) places. From the front you can see two horizontal bars. The middle Standard Toggle has a "Toothy Grin". You can see five (5) horizontal bars from the front and the entire plate adjusts up and down. The rightmost Chrome Toggle has just one (1) horizontal bar and again the entire plate adjusts up and down. Each of the Toggle lever lengths are different. The longest being the Standard Toggle and the shortest being the Chrome Toggle. When the Silo doors are open, the stamping on the Standard and Chrome Toggle say "PAT NO. ON PKG." while the Serial Toggle has no stamping on the blade tray. And finally, the Serial Toggle has a serial number stamped on the base plate; the Standard Toggle and the Chrome Toggles have their date codes stamped there. There are of course internal differences too, but let's get to the pictures!!!!