There seems to be some confusion about clipper heads and what blades they take.
If you use a heavy duty horse clipper, it will either have a head that takes Wolseley, Heiniger or Lister style blades.
Heiniger style clipper heads
The Heiniger style clipper has a more traditional type clipper head where you physically have to place and align the blades into the correct position before you can clip.
Inside the clipper head there are consumable parts that are susceptible to wear and tear, but these can always be replaced.
The laminated springs move the blade drive carrier from side to side and the cutter (small front clipper blade) has to be placed on to the carrier, with the back comb (large back blade) positioned on to the back of the clipper.
On this type of clipper you must always ensure that there is a good leading edge and the comb must always protrude approximately 2-3mm in front of the cutter, otherwise the clipper will not work effectively and it will feel as if the clipper is just brushing or pulling at the hair.
The purpose of the comb is to lift the horse hair up and feed it into the cutter. If you refer to your manufactures instruction leaflet, it should always tell you how to set up your blades.
A2 Lister style clipper heads
The Lister and Masterclip V-Series clippers take a more modern blade system which is known as an A2 blade. 
This type of head is very easy to use as the blades are placed directly into the head and no alignment is needed. The tension is set and then the clippers are ready to use.
There can get sometimes get confusing as Wolseley also use A2 blades, but the holes on the back comb are set further apart so these two styles of A2 clipper blades are not compatible. With this in mind, it is always worthwhile checking with your brand of clipper to see which blade it takes.
On a Lister style clipper or Masterclip V-Series, the distance between the two holes on the comb is 5cm.
A2 Wolseley style clipper heads
Wolseley clippers have a similar clipper head stystem to the Lister style clippers and they also take A2 blades. The difference being that the distance between the holes on the comb is wider measuring 6cms.
