Size: 16.5VAC 50VA NPP1650P 16.5 V AC 50 VA Auto-Resetting (PTC) Fused Secondary 3 Prong Plug, Grounding Prong & Terminal. Efficiency Level VI Electrical outlet mounting tab UL & CE Listed, Wire Strain Relief, Lifetime Limited Warranty Typically used on alarm systems, gate openers, doorbells, etc. Compatible with but not limited to (Press Ctrl + F and search for your model): MG Electronics MGT1650 PWS-1650 ELK TRG1250