Andrey Rublev has officially switched to Head Gravity Pro racquets. Rublev has been playing with a blackout racquet for some time. He was also apparently under a racquet contract with Wilson, which just expired. 

Andrey Rublev was playing with a Wilson Six One 95 until a year ago before switching to a blacked-out Head Gravity Pro. Alexander Zverev also endorses the Head Gravity Pro.

Head Gravity Pro is arm-friendly with a flex rating of 62.  The large 100 sq. in. head gives a big sweet spot for players to hit through.  With an 18×20 string pattern, the racquet has excellent control and touch.

Head GravityPro Specs

Length 27 in (69 cm)
Head Size 100 sq in (645 sq cm)
Weight 11.7 oz (332 gm)
Balance Point 12.75 in (32 cm) 6pts Head Light
Construction 20mm/20mm/20mm
String Pattern 18 Mains / 20 Crosses (18×20)
Flex Rating 62 
Swing Weight 332