Racers asked - TLR engineers listened! The open ended ball cup set allows all 22 races with HD turnbuckles the ability to remove and adjust their ball studs and spacers without need to pop off their ball cups. The set includes the proper quantity of ball cups for all 22 vehicles, regardless of configuration.
Maybe TLR made a running change (my 22 4.0 was purchased here on the 25th of Jan 2018), who knows, but they stay on just fine.
Nice and easy to thread the turnbuckles into, also, I was dreading the usual 'turnbuckle hands' when building a new kit, I was pleasantly surprised when they spun right in with a lick of black grease.