The club of world-class number eight forwards is an elite one.
You can almost count them out on the fingers and thumb of one hand.
Kieran Read, Sergio Parisse, Toby Faletau, Billy Vunipola, Louis Picamoles and Jamie Heaslip just about covers the current lot in operation.
While Ireland's Heaslip has been a model professional all his career, Picamoles has had to make-do with the French system which operates on a more 'laissez-faire' basis.
The professional experiment of Picamoles moving from the warmth of Toulouse to the relative discomfort of the Northampton Saints environment in the East Midlands has been a windfall for his new club and his country.
Quite simply, Picamoles looks leaner and meaner this season than he has for some time.
"He is definitely one of the top 8s out there and has been for a long time," said Heaslip.
"I played enough against Louis and seen enough tape on him to know he is a bloody good player.
"He is a big man, surprisingly dynamic.
"I don't think he gets enough credit actually for being a footballer.
"Some people just think he is a huge man. I think he is a really gifted footballer."
Heaslip offered up a personal point of view on Picamoles' feel for the game as a primary weapon.
"He's able to assess the flow of the game, the dynamic of the game where the opportunities lie in it.
"Obviously, he has got a great array of skills and assets and is a very hard man to take down.
"Even if you do tackle him and stop his momentum, he is such a big man he always manages to get an offload as well.
"(He) keeps that point of attack moving which, as the defending side, is quite hard because you have no ruck to set your system from.
"It always makes it that bit harder to defend against," he stated.
Leinster have already had a recent taste of Picamoles in the Champions Cup.
The difference there was that the Frenchman was not surrounded by the list of gargantuan men Guy Noves will put in front of him at the Aviva Stadium on Saturday.
"This year alone we had him against Northampton. You can see he is doing good things with that team and is bringing that form through."
Broadening out the argument from the individual to the collective, Heaslip has never known anything other than a fiery French challenge.
They should have taken England's unbeaten record at Twickenham. They did put a stop to Scotland's trot at Stade de France.
"Look, we are under no illusions, to remain competitive in this competition, this game this weekend is a massive hurdle in the way.
"It is a massive opportunity and we have a lot of work to do," he said.
There will be no room for the sort of start against Scotland that could make all the difference to France's outlook.
Give the Les Bleus a sniff and they can quickly turn into bloodhounds.
"France are playing some really good football," issued Heaslip.
"They are in a similar enough position to us so it is going to make for an exciting time anyway.
"But what an occasion to be involved in, ye (media) all sensed the atmosphere during the November series.
"That excitement was heavy in the air."
Three months later, Ireland have rekindled the feelgood factor from their exploits in Rome.
The Grand Slam is gone. The Triple Crown is gone. But, the Six Nations championship is still on.
"It just gives you a kind of shiver up your spine in terms of trying to be the one that runs out there on Saturday and to kind of leave that jersey in a better place and leave that team in a better place."
The fact Heaslip has extended his national contract right up to the 2019 Rugby World Cup in Japan indicates one goal that surpasses all others.
"There is one thing I haven't won that I would like to win," he said.
"I like winning. I think any professional player that has ambition (does).
"I have been lucky to have a lot of success.
"It actually makes you hungry for more, to be honest.
"It makes all the crazy stuff that we do, sacrifice-wise, family-wise, friends-wise, pay off in a big, big way.
"That is something that drives me."
Long before the World Cup, Ireland have to take their steps one big game at a time.
"You might have that long-term ambition," noted Heaslip.
"But, one thing I have learned is that when you start looking down the road it is the thing in front of you that kills you.
"You have to keep your eye in front of you and what's going on."