Scalpels are a necessary piece of equipment for every hydroponic gardener, they're cheap and multi purpose!
Scalpels are mainly used to cut clones, in order to successfully transplant a clone you must first make sure that you cut it right. One clean cut must be made – without crushing the stem!
It's much safer to use a scalpel than a regular cutting implement.
Scalpels can also be used for many other jobs around the grow room from cutting sheeting into specific shapes it pays to have a scalpel around when you need one and they're incredibly cheap when you compare the small amount it costs to have one against all the benefits, especially if you're taking your own cuttings!