40 mm, yellow gold case. The Automatic 4030 Rolex timepiece is a stunning choice. Crafted in 18k yellow gold with a Tachymeter bezel, the 40mm case holds an elegant white dial featuring 8 diamond hour markers and Arabic minute markers at 3, 6, and 9. The luxurious ensemble includes a Rolex leather Alligator strap with an 18k yellow gold Rolex Oysterlock clasp.