It describes HA, HK, and LGD series boxes with dimensions ranging from 100-415mm in length, 105-323mm in width, and 75-140mm in height. The 19 inch dimension includes the edges or ears that protrude from each side of the equipment, allowing the module to be fastened to the rack frame with screws or bolts. Common uses include computer servers, telecommunications equipment and networking hardware, audiovisual production gear. This guide covers standard box sizes across every major industry, explains the difference between internal and external dimensions, breaks down carrier-specific size requirements for USPS, UPS, and FedEx, and gives you practical tips to find the right fit for any product. All Rights ReservedGray; Suitable for 1 piece of 1 × 16 (or two pieces of 1 × 8) blockless type PLC splitters; With the adaptor panel for max. 16 pieces of SC or duplex LC (SC type); Adaptors and PLC splitter NOT included; 1 midspan port and 16 drop cable ports; Dimensions (mm): 306 (L) ×253 (W)×92 (H); Wall mounting. This document provides specifications for various distribution boxes including dimensions, mounting sizes, and number of ways. Dimensions included are length, width.