These are high-quality, 1/4" hex-shanked screwdriver bits.
The hex shanks on the longer sizes are grooved for use with quick-change chucks. Each bit is machined from chrome vanadium molybdenum tool steel and is hardened to Rc59-62. These will last much longer than normal bits, especially when used in cordless drills or power drivers.
There are many advantages to extra-long screwdriver bits.
First, they let you get into areas you cannot reach with short bits because your drill chuck (and maybe the whole drill body) gets in the way. These 6" long bits let you reach into corners, through framing, past skirting boards, etc.
Second, the extra length gives you much better visual alignment with the screw; therefore, the bit seats better and you experience less cam-out. As a result, your bits last longer, although these, at Rc60, are very durable anyway.
Third, you can easily make your own screwdrivers. You just epoxy these bits into handles. All bits are 1/4" hex with quick-change shanks. 6" long.
Prices are per bit. Quantity discounts apply when five or more of the same size and style of bit are purchased.