These are high-quality, 1/4" hex-shanked screwdriver bits. They come in four lengths and are available in square recess and Phillips types.
The hex shanks on the 1 15/16" and longer size bits 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.
The extra-long 6" bits 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. You can reach into corners, through framing, past skirting boards, etc.
The extra length also gives you much better visual alignment with the screw, so 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.
To make your own screwdrivers, you can easily epoxy the 6” bits into handles.
Prices are per bit. Quantity discounts apply when five or more of the same size and style of bit are purchased.