Abu Number and Letter Designations and Meanings Baitcast reels are also known as Conventional Reels or Multipliers. I think England and Europe refers to them as "Multipliers" more so than anywhere else, but if you hear the term used then you'll know what it means now without having to do what I did and say "What's that???" The numbers on Abu reels are set as series first ... the first number means what size the reel is and each of the first numbers will have several models in that same spool size. For instance. 7000, 7001, 7500, 7800 and I think that's about all the different numbers in the 7000 series. The 5000 and 6000 series had over 100 different models in those series so I won't go through all of them but I'll give you and idea of what the numbers and letters represent. Starting off with the 7000 series reels. The 7000 was the base model number but it had several models that were labeled 7000's and most of them were 4.1:1 gear ratio which meant for every one complete turn of the reel handle the spool would turn 4.1 times. 5.3:1 means for every 1 complete turn of the reel handle the spool will turn 5.3:1 times. so the 5.3:1 is faster than the 4.1:1. How they achieve this is by making the gear that's being turned by the crank handle (the big gear) bigger on the 5.3:1 than the 4.1:1 and the small gear dog that engages the spool smaller on the 5.3:1 than the one in the 4.1:1 reels and sometimes the number designation or the letter designations change from reel to reel to signify that this model has 4.1:1 gears. It won't say that but when you're ordering parts for the gears or whatever you need from abu you give them the make of the reel or the reel foot number and that tells them what parts are needed for that particular reel so if you order parts for an abu reel be sure to have that reel in front of you when you call the 1-800-abugarc number. There are a lot of different reel foot numbers in the same model and series so you have to have the reel foot number to give to them because the very first abu 6500c3 has a few design differences over the years to the latest one. Probably about 8 to 10 different reel foot numbers over the years for the abu6500c3 so on some parts like the side plates and components in them may be different from an early model to a later model. I think the early 6500c3 had squared off side plates and some of the later ones had the ergonomic and even some of the later ones have the square ones like the 6500CSC3 mag-x is a later model reel but it has the square side plates and different clicker and stuff. The 7000c model was the red model and what the c signifies is that this reel has bushings that the spool turns on instead of bearings. The 7000c3 has bearings instead of bushing and the color of the side plates are aluminum looking silver. The 7000c4 was the lever drag reels and they'll probably have LD on it as well but I don't remember The 7001c3 just means that the reel is for left handed people the last number being 1 always signifies left handed reels. The 7500c3 just means that the gear ratio is higher at 5.3:1 and the color of the side plates are chrome with black paint insignia. The 7000ctc3 is the designation for non-levelwind reels. All of them with CT on them means they don't have a levelwind The 7500ctc3 was black and I think they had higher gears. The 7800c3 was the exact same reel as the 7000c3 but had gold plated side plates and spool ... they were great looking reels. The reels with the N designation means they're the Narrow spooled reels. So now we've got an idea of how this goes on the 7000's and I think I listed about all of them except maybe the Syncro and all the Syncro reels just had a weird drag release that would allow a fisherman to pull backwards on the handle to loosen the drag off. They didn't go over well I don't think. Too hard to work on and lots of problems with them. The CS designation on all abus was a counter to the CT counterpart when a reel was available in CT they also made one in that model as a CS model that designated that this was a levelwind reel when the same reel in the non-levelwind was the CT model. Confusing ain't it! Example would be the 6500CTC3 MagElite or Mag-X. They named them MagElite but due to a trademark infringement some years back, about 1999 or 2000 they had to change the name to Mag-X to avoid court battles so the MagElite is the same as the Mag-X but like I was saying the 6500CTC3 Mag-X was/is a magnet backlash controlled non-levelwind reel. It's counterpart with levelwind was the 6500CSC3 Mag-X. Now it makes sense doesn't it ... this is a special edition type deal where some people would want the reel in both levelwind and non-levelwind. The Non-levelwind version was popular with a lot of the Competition Casters that couldn't get the Ultramag III reels as they were discontinued many many years ago. 6500csc3 Mag Levelwind reel. 6500ctc3 Mag Non-Levelwind reel. The different between the 6000 and 6500 is the ultracast spool in the 6500's and the solid spool shaft in the 6000's. Below is a picture of the 6000 spool with the solid shaft on it. The bearings or bushings for this style spool were located in the side plates just like all the 7000 series reels. The designation of 6500 usually always meant that that reel had the UltraCast spool that slid onto the shaft that was connected to the right hand side plate and had the bushings or bearings located inside the spool as shown in the photo below. The numbers 13472 shows the bearings that are to be inside the Ultracast spool as well. This whole assembly slides onto the shaft that's on the right hand side plate. Some of the 6000's had ultracast spools too. Like the 6000c red model but it had bushings instead of bearings in the UltraCast spools. Which was about the only difference between the 6000c and the 6500c3 as well as the color of the side plates. The 6600 sports a heavier frame or is supposed to and some of the leverdrag reels are 6600's like the one shown in this photo below. The leverdrag reels aren't very good for casting or nearly as good as the 6500c3 or the ultimate casting 6500 which is the 6500ctc3(nonlevelwind)Mag-X or 6500csc3(levelwind)Mag-X. The leverdrag reels are more for trolling than anything as they're easier to back the drag off on and tighten it up when trolling so that it's easier to get the rod out of the rod holder by having the drag set lighter then tighten it a little to fight the fish once you get the rod out of the rod holder. There are literally too many differences in the 6000 series reels to list and a lot or most of them are marketing strategy to get people to buy more reels. For instance if they just made 7000c3 reels for that series then there wouldn't be any need for you to buy a new one when the 2 or 3 you've already got are working fine. Now if they throw another letter in there and change them just a little that will give you an incentive to buy a new reel. Some even get named 7000 Pro Rocket and change the side plate color and slightly higher gear ratio 4.3:1 which isn't even enough to notice. Some are limited editions. Some are species specific collector reels. These are all marketing strategy or mostly for that as people that catfish might be more prone to buying a 6500c3 catfish special reel when they've already got several 6500c3 reels. The only thing different there is that they've got the name stamped on them and maybe a little catfish logo.