CCMS 1500 – HCFA Self-Seal Window Envelopes for Claim Forms1500 – HCFA Self-Seal Window Envelopes for Claim Forms (No. 10-1/2) 4-1/2″ x 9-1/2″, White with Inside Security Tint – 100 ENVELOPES CMS 1500 – HCFA Self-Seal Window Envelopes for Claim Forms Size: No. 10-1/2, 4.5 x 9.5 inches White with Inside Security Tint Press and Stick, Easy to Seal Package of 100 Envelopes