【Switch/Charger/Round USB Socket Panel】 MAXWIN Expansion Cover. 【Easy-to-Understand Design】 The inner diameter size is approximately 30mm. 【PC + High-Temperature Flame Retardant ABS Resin Material】 【Easy Installation】 You can insert the item into the switch hole and fix it with screws before use. Easy to install, can be mounted horizontally or vertically. Body Size: Approximately 5 x 15 x 7.7cm (3 holes)