“LNL 234/678 Comparator Set 6 Description Lock-N-Load 234/678 Comparator Set 6 Proper length rounds are fundamental to accuracy. Make precise measurements with this tool. Includes: – Comparator body – Insert: .224″” (5.56mm) – Insert: .243″” (6mm) – Insert: .257″” – Insert: .277″” – Insert: .284″” (7mm) – Insert: .308″” (7.62&8mm”