This arrow roller is made in house. It is designed to be use only with wooden arrows. You simply identify where the bend in the arrow shaft is and then apply pressure whilst rolling over the high part of the bend. What this is doing is crushing the fibres of the shaft. Whilst this sounds brutal and you would imagine it impacts the performance and properties of a shaft, I have never noticed any change in performance of an arrow however many times I have straightened it.
That said, when I make my custom arrows for customers I ensure the shaft is perfectly straight prior to measuring the spine!
The roller is made to last. It's main body is made from 30mm Delrin rod with a slot milled out to take a stainless steel pulley wheel with a quality bearing. The pulley is held in place by a hidden grub screw and the handle/rod is cureved at the end to comfortable fit the palm of the hand. The roller fits both 5/16ths and 11/32nd shafts.
Since the vast majority of wooden shafts don't arrive straight and don't stay straight for long if shot in woodland it's essential for any archer looking to shoot woodies in a half serious way to have the know-how and tools to straighten them out.