A stripping basket is a basket, or on other models more a plateau, that you tie around your waist using a strap. You put your line in the basket while stripping it in, so that you won't stand on your line. Due the spikes inside the basket your line will not get tangled. On some models you have cutouts on both ends so you can lay your rod on it while changing files. It's especially useful in places where your line get easily get tangled: on rocks or when there's lots of plans and grass around.