[Definition] Also called the choke collar or check collar, the training collar is a length of metal-link chain with a large circular ring on either end. The chain is slid through one of these rings and it is slid over the dog's head. When the dog displays an undesirable behavior the collar is snapped then released to get the dogs attention. This is primarily used where dog training includes leash corrections. [Tool] 
Training collar
T r a i n i n g c o l l a r
P r o n g c o l l a r o r p i n c h c o l l a r
R a d i o - c o n t r o l l e d c o l l a r s
M a r t i n g a l e c o l l a r
H e a d c o l l a r
N o - p u l l h a r n e s s
D o g b i t e t u g