Most lasercutters have a honeycomb to place the workpiece on, when you have slightly curved materials it can cause focus issues and you need to pin it flat to the table. One way to achieve it is by using nuts and bolts, but that can be a hassle with one hand underneath the honeycomb (and also messy with soot). The pegs are 10% thinner at the tips so they can be pushed into the honeycomb to pin down your workpiece in place. The material thickness is also written on them for easy organization. Parameters are: 

hexagon size

length

material thickness

wall thickness

I recommend printing in the most temperature resistant material you have.