They retail at about £35 - £38. I got mine from Derby House (eek see my other recent post: i don't shop there any more!) and found they made no difference with my big hunter who pulls alot.
I saw this on the Central Horse News Forum in the 'tips and tricks' bit;
" You can buy Flex reins for some ridicuolous amount of money, when you can actually make them like I did;-
When schooling a friends new horse, he used to snatch at the bit all the time, due to hardly being ridden let alone on a contact. I saw these flexi reins and thought of him, but for what they actually are, they seemed a bit dear.
So I had a rummage around at home, and found some old elasticated leg straps from a previous NZ rug. So away we went (with mums sewing skills).
All I used was;
two small clips that would clip to the bit rings
a nice piece of elastic which was sewn onto the slips and onto the rings the other end.
a ring at the other end to attach the reins to.
This worked as well as a proper flexi rein would have I am sure, and cost nothing to make. I still have them now. I wouldn't go for a days hunting in them, but they do the trick for a bit of schooling or hacking. They worked for this horse, who now is ridden without them and doesn't snatch "
My mare pulled like a train but if dropped contact for a second she would try to take off. I used these after seeing them cheap on eBay and decided to get them to save my poor arms
They worked really well and we are starting work in normal reins again now. YO is using them on her youngster and he's going very nicely in them.
Bugly - the flexi reins and others are inserts, so if there horse was to bolt you'd get a solid pull and if the elastic broke you wouldn't be up the creek without a paddle.
Probably works just as well, but I wouldn't hack out in your version!!
The quick fix was just something I copied of another forum that someone has posted>I have not tried that. I have got the proper version but have noticed no difference with my 'puller'.