Zebra delguard mechanical pencils have a weighted cylinder inside the barrel that advances the lead when you shake the pencil. The weighted cylinder adds a heaviness to the pencil, but it makes the pencil feel very sturdy and stable.

The leads write nicely and are pretty durable. The lead is thick enough to not break using normal writing force. It's the best writing experience with a mechanical pencil thus far.

The click works perfectly fine and the proper amount of lead comes out per click. The eraser twists up and down, both movements seem smooth.

The lead gets jammed in them, the tips crack and overall, they were much more trouble than they were worth. The eraser is also useless. I find myself having to grab a wooden pencil just to use its eraser on any mistakes.