Turfmasters Mouthing Bit
The Straight bar is a very mild mouthpiece. The bit puts pressure on the tongue and lips (corner of the mouth), it does use slight pressure on the bars depending on the size of your horses tongue. This mouthpiece would not be suitable if your horse leans on the bit or if they tend to take hold of the bit, also may not be suitable for the breeds with larger tongues as they may find this uncomfortable.
The loose rings tend to make the horse relax his jaw and chew the bit.