Elastic training aid made from 1/4" tubular elastic with adjustment on the poll. To fit, the elastic passes through the bit and clips on to either the saddle dees or girth.
I bought these to help get my horses working long and low off of pressure (poll & bit). They're decent (not too severe tension) but the snaps are cheap plastic. The adjustment tap (at the poll) also can easily be pulled against by the horse and the reins loosened, so they're not very effective in terms of securing certain degrees of tension. On first use, the plastic snap on one side broke with very little effort when the reins were at their loosest. This means I have to tie off both sides to get equal pressure or switch sides when I lunge. Not ideal. For $11, these are glorified bungee cords.