– 6 – BLOCK DIVISION, INC. BLOCKPARTNUMBERINGSYSTEM.Block Division’s numbering system is an easy to use methodology for part numbers. The first part of the numbering system is the sheave diameter (in inches). The next number is the style (eye, flat, fixed eye or hook), followed by the number of sheaves (single, double, triple). The “SN” at the end indicates whether the product is a Snatch Block, while the letters “SL” indicate if the product includes a Safety Latch. There is also a “C” for Carded products. E D 0 1 5 4 8 – 2 – S N – S L – C A B C F A – Sheave Diameter 1.5" 2.0" 2.5" 3.0" 3.5" B – Style 4 Eye 5 Flat 6 Fixed Eye 7 Hook C – Indicates Double Sheave D – Indicates Snatch Block E – Indicates Safety Latch F – Indicates Card Pack Black-Oxide Finish Now Available.