Use this envelope with inserter equipment to send recipient 1099-R forms. The security tint and cellophane windows ensure the privacy of information. To confirm compatibility with your software, request a free sample or call our customer service team. Specifications:Size: 5 3/4" x 9"Top Window Size: 11/16" x 3 5/8"Top Window From Left Side: 11/16"Top Window From Bottom: 3 5/16"Bottom Window Size: 11/16" x 3 5/8"Bottom Window From Left Side: 4 5/16"Bottom Window From Bottom: 1 1/8”Weight: 24#Material: White WoveInk Color: BlackFlap Opening: LongSeal: Moisture