Confused about replacement Brother cartridges

JohnB47

Edit: Never mind guys. I decided just to go ahead and insert them cautiously. All seems to have worked, although the need for two cleaning cycles seems to have used up around 10% of the ink! I hope the little volume gauges are pessimistic.

Hi all. Subsequent to my other thread, I have now received a set of compatible carts from 'Cartridge People'. I have checked and these are definitely the ones meant for my machine.

The first thing I noticed is that the little tubular spout that feeds the ink into the printer isn't terminated like the previous ones (originals and compatibles from Choice Stationery Supplies). On the previous ones, there is a simple sealing strip across the tube, which gets punctured as you push the cart in. On this new set, there is no film but what appears to be a sort of collar. I can see it move if I pull gently - it would be easily pulled off.

When I look into the end of the tube, it is concave with a little metal pin at the centre. This part stays in place as I prise the collar off. Am I supposed to push this collar off before inserting? There are no instructions with the carts.

I don't want to damage anything, so any help appreciated.