Kotobukiya's line of scratch building accessories known as Modeling Support Goods, or M.S.G., is pretty unique in my experience. They are a large number of different injection molded generic shapes and parts suitable for adding to models of all kinds. Apparently targeted at those scratch building Sci Fi ships, vehicles and mecha. They are still worth having by those who build aircraft armor and ships.
Each package contains one or two sprues adding up to about a 60 square mm of area of components with each package concentrating on a few shapes in various sizes. There are packages of round and square plates, packages of rocket nozzles, rivets, nuts and portholes. There are rings, slots, vents and telescoping hydraulic cylinders. The variety is amazing and they are all injection-moulded styrene. This makes them easy to use and modify. The line also includes ABS robot joints as well as PE mesh and various springs and cable products in wire and fabric.
My two reservations regarding these parts are scale size and detail crispness. The pieces are generally on the largish size, making their usefulness for smaller scale models somewhat limited. The molding detail is a bit on the soft side. Parts tend to have somewhat larger corner radii and draft angles than the better injection kits were are used to seeing. There can be some slight sink marks in some of the thicker moldings, though not very many.
If you scratch build, I urge you to take a look at the items in this line and see if they solve some of your trickiest problems.
The Kotobukiya site shows all the parts and when you click on the individual sets you will get the actual part dimensions so you can tell if the set is right for you. These items are all available from Hobbylink Japan.
SUMMARY
Despite a somewhat odd name, Kotobukiya's Modeling Support Goods line of scratchbuilding details offer a lot of interesting shapes for a great many types of projects. Aimed at those who scratchbuild spacecraft and