It may look like a toy truck when at the bottom of the mine, but the wheel is twice the height of its driver and the truck itself is the size of a two bedroom semi.
By Briony Hale
BBC News Online in Botswana
These monster trucks have transformed the work of diamond miners - and the profits of mining firms - beyond all recognition.
In just one journey, the monster can transport as much ore as a one kilometre line of normal pick-up trucks.
"The trucks keep on evolving, and are still getting bigger and bigger," says Junior Keyser, the pit operations manager at De Beers' Venetia mine in South Africa.
The tricky part, he explains, is reversing: there are blind spots all around.
The easy part is that a computer in the cab tells the driver what to do via picture messages sent to a mobile data terminal.
Twenty-seven-year-old Jabulile Vandepitte shocked her whole family and her husband with her choice of career, not to mention the size of her truck.
But she enjoys driving between the pit and the crusher at Orapa, the world's largest diamond mine in Botswana.
Jabulile climbs aboard her truck (with the help of a ladder)
"You know when you get into the truck that there will be no stress," she says.
"You just sit there for eight hours and then you knock off. It's comfortable and air-conditioned."
It takes about three months to train up a driver, but five years before they operate at maximum speed and skill.
Her time in the control room - which ultimately decides where the trucks will go - proved to be a much more fraught experience however, and she much prefers to be out in the cab.
Safety, and the need to avoid collisions, is imperative.
Some miners are fitted with chips in their shoes that sound an alarm to warn the driver and the control room of their proximity.
And soon the trucks will also be linked to a new alarm system that sends off a warning if two vehicles get too close to each other.
Safety aside, the priority is efficiency, measured by how many tonnes of ore can be transferred from the pit to the crusher in the space of an hour.
Diamonds: the meaning of life for monster trucks
The monster trucks can travel as fast as 70km an hour on the level, but only up to 15km when coming up the steep slopes out of the pit.
New mechanical electrical systems are being developed to replace diesel engines and get the trucks moving faster up hills.
The speed at which the truck can collect its load is also critical.
The position of the monster trucks themselves can be tracked to under a metre. But the real precision work comes when loading the ore.
The shovels and bulldozers are tracked to within a centimetre, using seven different satellites, so that they can find the most level surface, says Mr Keyser of De Beers.
The flatter the surface, the greater the stability and the faster they are able to fill up, he says.
Orapa owns 45 monster trucks, each one carrying two full loads of 190 tonnes of ore to the crusher each hour.
Last year the mine yielded 14.3 million carats and Botswana sold $2bn worth of diamonds.
At 15 million rand a piece (£1.4m) monster trucks do not come cheap. But there is no doubt that they are earning their keep.