table saw push table to cut 45%

kb seen on tv but cant remember where some one built a wood sled that run in both 3/4” run rails and was set up to cut a perfect 45% angle for right and left side i make a lot of picture frames with some fancy wooworking on the face but some times when i cut a miter on cut off saw there not 100% this looked like a better deal or does anyone have a better idea . thank you guys kb

-- ken kindle