L/R-ΔLoc (L/R Delta Lock) was selected and adopted.
This year is the 35th anniversary of sales of G-SHOCK. It is the one and only iron plate brand in the history of watches that has exceeded the cumulative total of 100 million units shipped.
Before G-SHOCK, it was assumed that watches break when dropped, but after overcoming many hurdles, a unique shockproof structure was invented. It was the birth of a technology that plays a central role in toughness. It was a new beginning for watch history, and this legacy of toughness continues to be handed down; G-SHOCK continues to pursue the ultimate toughness over the time.
The top model G-SHOCK MRG-G2000R-1AJR was released in October 2018 and is equipped with “L/R-ΔLoc,” the screw that never loosens. NejiLaw has stepped up to the next level as well.

Development Story
G-SHOCK, that has built a new concept of toughness for watches, finally contacted NejiLaw in search of further advancement. Although the L/R Neji (bolt and nuts) had already been established as a non-loosening screw, there were still many issues to resolve. Not only were there restrictions of the materials and surface treatment, but also the screw diameter of the bolt was only 1.6 mm. Moreover, the permanent fitting latch structure could not be used because it needed to be removed without breaking during repair. Thus, a new solution was invented: The L/R- ΔLoc, or “Delta Lock,” a new mechanism created by Hiroshi Michiwaki applying elasto-plastic dynamics.

L/R-ΔLoc (Delta Lock) Fastening Mechanism
The three vertices of the triangular-prism-shaped Δ (delta) part of the first mounted left-handed “L-nut” plastically deform the cylindrical part of the right-handed “R-nut” that is afterwards mounted.
The L/R-ΔLoc mechanism is set to “deformed isoperimetric” so that the outer peripheral length of the delta part and the inner peripheral length of the cylindrical part are almost equal. This cylindrical part is designed so that its deformation is within the plastic range, and when it is fitted to the delta part, it is configured so that it is pressed in the residual elastic range while accommodating a round object along the triangle. With this, it is possible to maintain a strong rocking state, and as a result, the two nuts are integrated and cannot be pulled out from the L/R bolt.
What is Elasto-Plastic Mechanics
Most objects can be deformed by an external force, but when they do not return to the original shape after being deformed, it is known as plastic deformation (permanent deformation). Contrarily, elastic deformation is a shape change that is self-reversing after the force is removed. "Elasto-plastic mechanics" is a product that combines these different properties.

The non-loosening “L/R Neji (bolt and nuts)”
Traditionally, screws are used in places where they should not be loose. However, there are no screws that never loosen. Inventor Hiroshi Michiwaki got involved in screws when the wheels came off of a car he was driving. This experience motivated him to develop a screw that does not loosen. One of the causes of looseness is the friction force acting between the thread surface of the male thread and the thread surface of the female thread. Although all screws depend on this mechanism, “L/R Neji” was an epic invention that locks with two nuts that rotate in the opposite direction had even discarded the spiral structure of the bolt which was viewed as “common sense” of screws.

From product description of CASIO COMPUTER Co., Ltd. G-SHOCK MRG-G2000R-1AJR:
Joint development with NejiLaw famous for its "Neji (bolt and nuts) that does not loosen," was carried out
to improve its vibration resistance. The world's first "L/R-ΔLoc (Delta Lock)" is equipped with a band connection that is extremely resistant to loosening. Based on the L/R Neji (bolt and nuts) that locks one bolt with two nuts that rotate in the opposite direction, the Δ-Loc applies elasto-plastic mechanics to prevent loosening due to vibration.
Click here for the G-SHOCK official website

To commemorate the mounting of L/R Neji (bolt and nuts) on the G-SHOCK MRG-G2000R-1AJR,
the 10x enlarged prototype of L /R-ΔLoc (Delta Lock) which is actually used in the G-SHOCK model
will be pre-ordered in limited quantities .
It is a large model with a total length of 233 mm.
If you would like to reserve one, please contact us by email below.
Details will be informed by return.

E-mail: deltaloc@nejilaw.com