These are well-designed bit holders. The regular holders accept any plain- or grooved-shank 1/4" hex bit and have a free-spinning sleeve you can grasp to give stability when starting a screw.
Designed to work with 1" insert bits, the Ringmagnet holders have a sleeve that slides to the tip of the bit, where a strong rare-earth magnet holds ferrous screws #10 or larger, making these holders especially convenient when working overhead or in hard-to-reach spots. The sleeve retracts as the screw is driven and releases when it seats. The Ringmagnet holders also accept longer grooved-shank bits; however, the sleeve has only enough travel for the magnet to engage a screw when using a 1" bit.
With either style of holder, bits lock in place with a light push; slide the locking sleeve forward and the bit pops up, where it is held, ready for removal.
Each style comes in two lengths – one for general use, and a longer version to extend your reach and for driving into a corner or nearly parallel to a surface. All have grooved 1/4" hex shanks for use in regular or quick-change chucks.