ALL girths have TWO Dee's for breast collar and rear flank attachment. The buckle shown used in photo above of the neo ENGLISH girth is not the buckle currently used.  The girth buckle used is as shown on the contoured leather girths and the “grippy” girth below.

Neoprene Girth: This black medical grade neoprene foam is the highest grade available and has a longer life than less expensive neoprene on the market. The 1-inch buckles (roller buckles on the English girth), and center Dees (front and back) are of high quality stainless steel and attached with special 10,000 pound test strength nylon webbing to ensure maximum strength. The buckles are attached so they pull against the edges of the main strip of webbing. This keeps the webbing from curling inside the neoprene tube, which can create a hard spot or lump that can sore the delicate skin of the elbow, or cut in at the sternum area. The thread used in the Neo-girth is heavy-duty 248 series for extra strength with UV inhibitor to protect against deterioration from sunlight. Even sizes only, starting from sizes 18 inches up to 54. 
English girths have ROLLER buckles and two Dee's

The no-slip grip neoprene girth:This all black non-slip textured medical grade neoprene girth is exactly what you need for those round horses and for saddles that slip.  This girth will give you the extra grip necessary to keep you in place.  Made from the highest-grade neoprene available for wet suit construction.  The neoprene is backed with only one layer of nylon cloth for reinforcement.) The neoprene is then turned inward so that the nylon will not be against the horses’ skin which can create heat and friction that can lead to galling.  This girth has a longer life than less expensive neoprene that tends to crack and fall apart, and can easily cinch sore your horse.  All the hardware is of stainless steel.  The 1-inch buckles (roller buckles on the English girth), and center Dees are attached so they pull against the edges of the main 4-inch strip of webbing, thus keeping the girth from cutting into the underside of the horse. The way the buckles are attached keep the webbing from curling inside the neoprene tube, thus avoiding a hard spot or lump that can sore the delicate skin of the elbow or cut in at the sternum area. The thread used in the Neo-girth is heavy-duty 248 series for extra strength with UV inhibitor to protect against deterioration from sunlight. ALL girths have TWO Dee's for breast collar and rear flank attachment. Even sizes only starting from size 18 inches up to 54. 
English have ROLLER buckles and two Dee's

Contoured Leather Girth: Give your mount a soft touch with this soft-sided girth. These girths have no stretch and are pre-molded to a curve to fit around the horse; the girth is shaped wide (6.5 inches) at the sternum underneath and narrow (2 3/8th) at the horse’s elbows. Excellent on round-barreled or mutton-withered horses due to this feature of fitting like "little saddles" under the horse, holding a saddle more securely than any other girth. The contour behind the elbow is excellent for those horses that have a narrow girth area, a large tricep muscle or those that have tremendous extension, especially performance horses. Even "cinchy" horses love this girth. These girths are complicated to make, but they’re worth the extra effort. First leather skirting is backed with nylon webbing and wet-molded to a curve. Next, neoprene wet-suit foam is placed behind the webbing and folded over the edges of the leather and sewn in place, giving your mount soft sedges that will not dig in. Then the neoprene is covered with a thin layer of  garment leather and sewn in place. The stainless buckles (1-inch roller for the English) and the dees are added so a breast strap and flank cinch can be attached. Finally, beautiful top grain leather (matching your saddle) is sewn on top just short of the finished soft edges. It’s the ultimate! Even sizes only. Starting from size 18 inch up to 54. 
 English girths have ROLLER buckles and two Dee's

The photo shows the difference between the contoured leather and the neoprene girths

How do people like this leather girth?  Read below
----- Original Message -----
From: "Erin R."
To: <hillview@springfield-sanborn.net
Sent: Tuesday, March 01, 2005 11:25 PM
Subject: Dressage Leather Contoured Girth

Hi Cathy, my name is Erin Roten and I recently ordered a size 28 leather contoured Dressage girth from you. Fabulous, fabulous girth. Only it is too big. So I'll be returning it for an exchange. Could you send me one size 26 and one size 24? I'll send back the one that doesn't fit. Do you still have my credit card info.? Let me know if I need to call you. Again, that girth is simply "it." Love it. Thanks, Erin "The Morgan Horse is one thing; all other horses are something else."

How do I know what size girth or cinch to purchase? You might need two girths sizes, depending upon how fat your horse gets in the off season and how much he shapes-up during riding. On western saddles, you should never be more than 6 inches away from the D ring on either side of the saddle and no closer than one inch. On English saddles your girth should be half way up the billets on either side. On both saddles, towards the end of and the beginning of the riding season, when your horse is either putting on weight or is fat from his time off, you will be on the outer edges of your billets or distance from the D ring. The opposite is true when your horse is in peak form, upper half of billets and closer to the D ring

Leather Rear Flank Cinch:  A rear flank cinch, properly used, holds the back of the saddle down, keeping it from tipping up. To adjust a rear flank, tighten firmly when on the ground so that when you are in the saddle the rear cinch does not hang more than one inch. These girths are top quality grain leather, with stainless steel hardware, a center strap and snap for attachment to your front girth. These are available in 3 inch or 6 inch widths. Even sizes only, state leather color.

Kwik Cinch Barney Buckle: Easy tightening for western girths. This unique buckle is thin and adds no extra bulk under your leg. The Barney Buckle turns any cinch into a Smart Cinch, for you can use this buckle on any size girth. Great if you have different size horses that you ride who require different cinch sizes or if you have difficulty mounting and dismounting because you can easily tighten your girth from the saddle! Remember, if you ride for long periods of time in warm conditions, your horse can loose up to 50 lbs. in body weight through sweating. So having the ability to do a "Kwik cinch-up" is wonderful. Made of polished stainless steel and leather. 3.5" x 2.5" w. For use on western saddles that have a 1 to 1 and 3/4 inch latigo belt. The Kwik Cinch stays with your saddle and can use used on any size western cinch. Selected as the top101 innovations for 2003 by Tack n’ Togs trade magazine.

English Girth Tightener: By using leverage, this "Belly Buster" will allow you to girth up even the biggest air bag of a horse! No more than 10 inches long you can take this tightener with you on the trail. Make girthing up fast and easy with this nifty device. (Warning: you can easily over tighten.)