Tae Kwon Do
Chung Do Kwon - The School of the Blue Wave
Stretching and warming-up are two of the most important items before you begin any exercise routine. Regular stretching not only increases your level of flexibility and overall performance, but also reduces the potential for injury.  Partner stretching and warm-ups are part of every Tae Kwon Do class. One partner stretch that is particularly helpful is called the “bow stretch”. However, when practicing at home it is difficult to do without a partner. There are many items on the market that you can purchase ranging from $30 up to over $200.

I made the one below for under $6 using PVC, a piece of wood 2x4, and 3 lag screws. It is very sturdy and works well. You can easily make it adjustable by adding a few extra holes in the middle PVC pipe, as illustrated in the official  SAKURA Leg Stretcher image. 
Step 1
Cut two pieces  of 1" Schedule 40 PVC at 3’ lengths for the outside (LEGS) and one 2 to 2 ½’ for the middle. (HANDLE BAR)

Step 2
Drill holes in your PVC that work with your size of lag screws (I used 4” lag screws)

Step 3
Attach 90 degree elbows to PVC using PVC cement.  You can extend the elbow with a 2-3" PVC that you can later wrap with tape or foam.

Step 4
Attach all components to your 2x4 piece (Here I use a 6” scrap piece of 2x4)

That is all that is too it!   Six dollars or less and a little time....AND you can spend the money you saved instead on TWO more Tae Kwon Do classes!!!