What equipment you decide to use with your show dog can
make a big impact on your dog and how he shows in the ring.
It's important to use equipment that is properly fitted and that
feels comfortable for you and your dog.

A martingale, also known as a limited slip or a greyhound collar 
is a collar that, when properly fitted, will close up enough to
keep your dog from slipping his head out, but not so much that it
will continue to close on the dog's neck and choke him. A 
martingale collar can be made from chain, nylon, leather or a 
combination. This is a properly fitted martingale:

The martingale should not be so small that it can close up overly tight 

around the dog's neck. A smaller martingale, that can continue closing 
if the dog is pulling, should not be used on a dog that pulls on the lead.

Slip or Choke collars
Choke collars, also known as slip collars are collars are made
out of chain, leather or nylon, generally. Choke collars close up as the 
leash is tightened. Because choke chains can be uncomfortable for the 
dog, they are something I do not typically recommend. If a dog is to use 
a choke or slip collar, he should be trained not to pull first so that he
doesn't get choked. Also, nylon is preferred over chain. This is a 
choke chain: 

All In Ones
There are several "all in ones" that are both a collar and a lead
in one. They come in a martingale style and also in a simple 
loop style that has a loop with a stopper that keeps it in place
on the dog. These are a great choice, particularly for smaller
to medium sized dogs. This is a custom made, kangaroo
leather all in one with a loop.

A Resco brand all in one lead with a kindness strap.

Martingale all in one show leads in nylon and chain.

Many of my clients use these British martingale show leads when 
training and some even in the ring. These leads are way under used
and can be a great choice for medium to larger dogs.  

If you aren't using an all in one, then you will need a lead to go with
your collar. Choose a lead that is as thin as you are comfortable 
using. Leather is usually the best choice. Leather show leads come in 
a variety of lengths and widths of flat leather or you might choose
a fancy, braided leather lead with beads.

Where to get equipment
With a simple online search you will be able to find a lot of
places to order this equipment. Some offer ready made
basic leads, others offer intricate custom made leads and 
collars with beautiful beadwork.  Check them out! -  There are a lot of great sellers on Etsy that
offer custom or ready made show leads. - Offers all in one martingales, rescos 
and more. - Offers custom made leads with beadwork. - Offers custom leather collars and leads. - Offers several types of show leads.

Dog Show Checklist
This is a list of items that you may need at the dog show. Some items
like a chair and ex pen will depend on the show site as there may be no room
for ex pens or chairs may be provided.

Crate and crate pad
Exercise pen
Dolly or wheels
Show Lead
Water and bowl 
Blanket, to put over crate
Grooming supplies (comb, brush, shears, etc)
Waterless or no rinse shampoo