These are "Shining Adjuster Screws" decorated with crystals on the top of L-shaped adjuster screws. Four types of PRECIOSA aurora crystals are available: * Pale Lilac Aurora: Pale purple to pink AB finish * Aquamarine Aurora: Pale blue AB finish * Light Colorado Topaz Aurora: Golden AB finish * Mint Green Aurora: Green AB finish AB finish was jointly developed in 1955 by Swarovski and Christian Dior. It is an abbreviation for "aurora borealis," and is a beautiful effect (finish) that changes color depending on the viewing angle. PRECIOSA is a Czech crystal brand, second only to Swarovski. The beautiful cuts, transparent glass, and stunning effects are truly impressive. The screws are compatible with L-shaped adjusters for violins and violas (Wittner, Stradpet, etc.). Screw diameter: JIS M2 Made of steel (gold-plated), with a pointed tip. Crystal: PRECIOSA flat back ss20 This product includes only one screw. Adjusters, tailpieces, and instruments are not included. When replacing the screws, it is recommended to protect the instrument with a cloth or similar material to prevent scratches.