A kit is bought for a job, not for a tool. The point of buying one is that the consumables that make the tool usable are in the case with it, which is what turns a purchase into something that works on arrival rather than something that needs a second order before it can be used. It also fixes the sizes: a kit brings consumables already matched to the tool rather than left to be worked out.
Hammer kits pair the tool with its chisels and come in long and medium stroke forms, since the stroke has to suit the work as much as the chisel does. Die grinder kits at 15 and 42 pieces bring the grinding points and a case, which matters most on a first purchase where the collet size is being fixed for the first time.
Impact kits pair the wrench with sockets in the matching drive, and a glow plug removal kit covers one specific recurring job rather than a general set. Blow gun kits at 19 pieces bring the nozzles and adaptors that make a gun useful on more than one fitting, with spray gun kits alongside them. Impact kits are sized by drive, so the sockets in the case suit the wrench they are supplied with.
Piece count is the headline but the contents list is the real specification, since two kits of the same count can serve different jobs entirely. A 14 piece stand deal and the Draper Storm Force 68 piece set cover a bench being equipped from nothing. The contents are stated per kit, and anything unclear goes over WhatsApp on 07754288583. Spray gun kits carry the same logic on the finishing side, arriving with the pots and nozzles already matched.