The Wolf Tooth Components 110 BCD asymmetric 4-arm chainring for Shimano cranks from the GRX Gravel line is only compatible with Shimano 12-speed chains, the so-called HG+ or Hyperglide+ chains. It features the patented Drop-Stop design, which provides better chain retention, dirt repellency and less wear. The Wolf Tooth GRX chainrings have four arms, an asymmetric bolt circle diameter of 110 mm and specially shaped mounting holes. Specifications: Application: Gravel Mount: 110 mm bolt circle diameter, 4-arm asymmetrical Teeth: 40 T, 42 T, 44 T, 46 T, 48 T, 50 T Gearing: 1x12-speed Technical Information: Material: aluminium (7075-T6) Chainline: 50 mm Compatibility: Shimano GRX 1x cranks Shimano 12-speed HG + (Hyperglide+) chains Features: Single chainring with Wolf Tooth Wide-Narrow design Same chainline as Shimano Original Made in the USA Note from the manufacturer: For very muddy conditions a chain guide in combination with clutch rear derailleur is recommended. Technology: Drop-Stop ST Wolf Tooth has invested countless hours in the design, prototyping and testing of their Wide-Narrow chainrings and has developed a highly innovative tooth profile. The right side of the chainring tooth has a different shape than the left side. The right side transmits the power to the chain and the left side opens a free space for cleaning off mud and dirt. Since the two sides have completely different functions, it makes sense to design them differently, true to the motto: extra reinforcement where you need it, less material where you don't. The right side of the Drop-Stop tooth is as wide as possible to distribute the load over a larger area, which also minimises wear. The left side of the Drop-Stop tooth helps to guide the chain, but it does not transmit any load. Therefore the left side is narrower than the chain roller. Wear is not an issue on this side, so Wolf Tooth was able to save material and create a better mud clearance channel. More free space means less friction and less change of the chain being dropped due to mud. In the ST version, the Drop-Stop tread is optimised for use on mountain bikes with Shimano Hyperglide+ 12-speed gears. The teeth are somewhat narrower overall. The wide teeth have a symmetrical trapezoidal shape (Symmetric Trapezoidal = ST) to accommodate the more extended inner edges of HG+ chains and thus guide them. The outsides do not touch the chain, unlike the narrow teeth and unlike Drop-Stop A and B.