A fellow is going on a tour of a factor

A fellow is going on a tour of a factory that produces various latex products.

At the first stop, he’s shown the machine that manufactures baby-bottle.

The machine makes a loud Hiss-Pop! noise.

“The hiss is the rubber being injected into the mould,” explains the elderly guide.

“The popping sound is a needle poking a hole at the end of the.”

Later, the old man reaches the part of the factory where  are manufactured.

The machine makes a noise: Hiss, Hiss, Hiss, Hiss-Pop!

“Wait a minute!” says the man taking the tour.

“I understand what the hiss, hiss is, but what’s that pop every so often?”

“Oh, it’s just the same as in the baby-bottle  machine,” says the elderly guide.

“It pokes a hole in every fourth .” “Well, that can’t be good for the the old man states.

“Very true, but it’s great for the baby-bottle business!”