We love these Nunn Finer Studs, because they're made from high-quality steel. These studs are sold individually and ordered by letter: A - Small Hexagonal Bullet: Good-to-dry conditions (hind) or wet conditions (front). B - Medium Hexagonal Bullet: Good-to-slick conditions (hind) as a pair or on the inside with a semi-spike on the outside, or in wet conditions as a pair (front). C - Full-Short Hexagonal Bullet: Wet conditions with deep footing (hind) or on inside with full spike outside. D - Full Hexagonal Spike: Grass in dry/hard conditions. Use on the outside, with a dull stud on the inside. G - Flat Hexagonal Road: Everyday use (front) in hard conditions. H - Semi-Hexagonal Spike: Good to dry conditions (front). Outside with a dull stud of the same height on inside to prevent grabbing. J - Hexagonal Bullet: Good to slick conditions (hind) as a pair or on the inside with a semi-spike outside, or in wet conditions as a pair (front). L - Large Hexagonal Bullet: Good to slick conditions (hind) as a pair or on the inside with a semi-spike outside. Also as a pair in very wet conditions (front). M - Semi-Square Small Spike: Grass or hard/dry conditions (front) or outside with a dull stud of the same height on the inside (hind). N - Semi-Square Medium Spike: Good-to-dry conditions (front). Used outside with a dull stud of the same height inside (hind). O - Shaped Square Road: Dry-to-hard conditions. Everyday use or on inside with a semi-small spike outside. Q - Full-Square Block: Wet conditions with deep footing as a pair (hind). R - Semi-Square Spike: Good-to-dry conditions (front or behind). Use on the outside with a dull stud of the same height on the inside. S - Full-Square Spike: Dry/hard ground on the outside only. Use dull stud on the inside. T - Small-Square Road Stud: For everyday use. U - Medium-Square Road Stud With Tip: Everyday use, dry-to-hard, conditions on the inside with a small semi-spike on the outside. V - Medium-Square Road Stud: For everyday use. X - Full Short Hexagonal Bullet, Everyday use (Front) in hard conditions Y - Hexagonal Spike, Grass in dry/hard conditions. Use on outside with a dull stud on the inside Z - Full Square Block, Good-to-slick conditions (hind and front) as a pair on the inside with a semi-spike on the outside