Clean Factory 4131 Movement Rolex Daytona m126519ln  “Cement Grey” Review vs. Genuine

Introduction

This Daytona exemplifies Rolex’s recent shift toward cooler-toned designs, with its subdued yet intricately layered dial quickly gaining favor among collectors. Clean Factory’s latest iteration—the “Cement Grey” Daytona (Ref. m126519ln-0006) powered by the 4131 movement—has been marketed as the industry’s sole replica crafted from original molds. But how does it hold up under close examination?

When evaluating a high-fidelity reproduction, it’s the minute details that determine credibility. Our analysis will break down its materials, finishing, and movement mechanics, supplemented by macro-level comparative imagery. The findings reveal that while certain elements achieve near-perfect replication, inherent differences in physical properties still persist.

Exterior Comparison

Materials

• Genuine: 18K white gold case (warm ivory tone), ~165g.
• Clean: 904L steel + PVD coating (cooler white), ~115g.
  Key Notes: The 50g weight difference is palpable but irrelevant unless handled. 904L steel matches Rolex’s corrosion resistance.

We can see that the two are almost identical in appearance.

Dial Detail Comparison

Dial Font & Hands Comparison

• Dial Font Printing:C Factory employs the same oil-pressing technique as the genuine watch, achieving 95% dimensional accuracy in font embossing. The shadow angles under directional lighting are optically identical to the original.
• Hands:Nearly indistinguishable even under 10x macro magnification.

Subdials & Dial Scale Nail Comparison

• Subdials: The three chronograph registers flawlessly replicate CD guilloché pattern without fracturing, including “floating” numerals on tracks.
• Dial Scale Nail:The shape is virtually identical, with C Factory applying identical rounded-edge polishing that achieves the same visual smoothness as the genuine piece.
• Lume: Both employ crystalline Super-LumiNova, though C Factory’s version demonstrates approximately 15-minute shorter persistence in controlled darkness.

Cerachrom Bezel Comparison

Both exhibit perfect congruence in typography and index spacing, achieving optical parity with the genuine.

Case Comparison

Because the materials are different, there are no other problems except that the colors are slightly different.

Rear Lug Comparison

The one made by Clean Factory is relatively close.

Caseback Comparison

After opening the back cover, you can see the details of the engraving inside. There is still a little difference in the engraving.

Movement Comparison

Specification Breakdown

Component	Genuine 4131	Clean (Shanghai 4131)
Accuracy	±2s/day	±5s/day
Power Reserve	72hrs	72hrs
Escapement	Free-sprung	Adjustable regulator
Finishing	Geneva stripes	Basic anglage

Critical Gap: Movement bridges lack genuine-level polish (brushed vs. mirror-finished), though irrelevant for a closed caseback.Based on the comparative analysis,the structural similarity can reach more than 90%.

Natural Light Comparison Shots

Due to lighting conditions and DSLR camera capturing, the dial color in photos may exhibit slight deviations. Please refer to natural daylight shots for accurate color representation.

Conclusion

Clean Factory’s Daytona m126519ln replica achieves top-tier craftsmanship in its dial and ceramic bezel details – virtually indistinguishable from genuine at normal social distances. Apart from the weight difference compared to the original, it maintains approximately 95% visual accuracy.If visual accuracy and cost considerations are your priorities, this model represents a technically competent option.