Pentel Function 357 Pencil PC1001

This is an incredibly useful pencil - the only one we know of containing three different size lead mechanisms - 0.3mm, 0.5mm and 0.7mm. Works like a typical multifunction pen - click down one of the three sliders on the top of the pencil to select the size. Press it further to advance the lead. Soft grip area on a largely transparent barrel.
Refill the leads by unscrewing the barrel and pulling out the relevant mechanism - again, much like a multifunction pen.