Crompton 4 pin metallic starter

10 years ago I was told about the very rare fluorescent starters that had 4 pins instead of the 2 we have today

This morning at the car boot sale I picked up a box full of starters and seeing that it had these 2 Crompton 4 pin metallic starters that would be used for 30-40-65-80W fluorescent fittings - I just had to get them

These will be handy for if I ever come across a fluorescent fitting that uses 4 pin starters