What do you call this drain blocker thing?

[candyjet]

I have a drain pipe underground, in the garden, which I have access to and need to block off.

I need a blocking thing, of which there is already one fitted elsewhere.

It is to block a pipe about 4 ins in diameter and apparently has a rubber bit in it, which when the device gets tightened, squeezes the rubber which expands and blocks the pipe.

I need to know what the proper name for these pipe blockers is, and if poss, where I can get one in the UK.

Thanks

CJ

 

[Bodgeit and scarper ltd]

http://www.toolstation.com/shop/Hand+Tools/Plumbers+Tools/Nylon+Drain+Plug+4+x+/d10/sd210/p20648

 

[candyjet]

Just the thing. Thanks!

CJ