Quick answer

A 42mm blue replica Drive is a copy of the Cartier Drive de Cartier, a cushion-shaped dress watch with a blue sunburst dial and Roman numerals. Most listings say 42mm because that is the widest point of the case, measured across the middle with the crown included or taken on a slight diagonal. The steel genuine version is usually quoted at roughly 40mm by 41mm, so a copy that actually measures 42mm will sit a hair larger on the wrist than the watch it copies. That one number shapes everything else you should check.

How the size really wears

A cushion case does not behave like a round one. The corners push out to the edges of your wrist, so a 42mm cushion reads bigger than a 42mm round watch with the same diameter. I look at three numbers before anything else.

• Lug to lug. On the Drive this is short, which is why a wide case still fits.
• Thickness. Anything past about 12mm stops sliding under a shirt cuff cleanly.
• Wrist size. At 6.75 inches or under, a 42mm cushion tends to look oversized. At 7 inches and up it looks right.

If your wrist is on the small side, a 40mm copy of the same reference will almost always look better than a 42mm one, even if the listing photos argue otherwise.

The blue dial is where copies are won or lost

Cartier's blue on this model is deep. It reads near black at the edges in low light and lights up to navy when sun hits the sunburst brushing. Cheap copies use flat blue paint with no radial grain, so the dial looks the same shade from every angle. Walk around a window with the watch in hand. A good dial changes. A bad one does not.

Then check the details that sit on top of the color.

• Roman numerals should be crisp, evenly spaced, and the same weight throughout.
• The rail track around the dial should be thin and continuous, with no blur where it meets the numerals.
• Sword hands should be polished, not painted, and should reach the minute track.
• The date window at 3 should sit level with the numerals, with no blue or white gap showing around the disc.

Movement options and what they mean for you

Most 42mm blue Drive replicas come with one of three movements. A quartz is thin and cheap but the seconds hand ticks, which no one who knows the watch will miss. An automatic built on a Miyota 9015 or a clone of an ETA 2824 sweeps properly and is the usual choice at the mid and top tiers. The most expensive copies decorate the rotor and bridges to imitate the look of the in-house caliber, and that decoration buys you looks, not accuracy.

Ask the seller which movement is inside and how many jewels it has. Vague answers are a signal. So is any claim that a copy contains a genuine in-house movement. It does not.

Case, crown, and finishing checks

Run a fingernail along the edge between the polished bezel and the brushed case sides. On a good copy that transition is a clean line. On a poor one it is rounded and soft. The crown should be fluted, should turn without grit, and should sit centered in the case flank with the cabochon set flush. Look at the caseback engraving under a lamp. Sharp lettering with consistent depth is a decent sign. Faint, shallow etching is not.

Strap and clasp

Most of these ship on a leather strap with a folding clasp. Check that the strap tapers evenly, that the stitching is straight and matches on both sides, and that the clasp snaps shut with one firm push. A clasp that needs two or three tries will annoy you every morning. If the strap feels like cardboard, budget for a replacement, because the strap is what touches your skin all day.

Price tiers and red flags

Below about $80 you get quartz, flat blue paint, and a case that photographs better than it feels. Around $150 to $300 you reach automatics with a proper sunburst dial and decent finishing, which is where most buyers should land. Above that, you are paying for decoration and small refinements.

Red flags I treat as final: stock photos only, no shot of the actual watch, refusal to send a short video of the seconds hand, and claims of "identical to genuine." Nothing at this price point is identical to genuine, and a seller who says so is telling you what you want to hear.

One honest note

A replica is a replica. It is not an investment, it will not hold value, and selling counterfeit goods is illegal in the United States, with real penalties attached. Wear it as a fun piece, keep your expectations in line with the price, and you will enjoy it far more.