Welcome Guest Hotel Keycard Key Card Envelope or Sleeve- Case of 10,000 High Quality Premium 100g Keycard Key Card Envelope or Sleeve, In stock-ships within 24 hours. Case of 10,000- 20 boxes of 500 for convenient front desk storage. 2 3/8" x 3 1/2" wide thumb-cut envelopes holds and protects 2 keycards. Front has box to write room number, back has general safety rules. Lock Tech Supply is a leading supplier to hotels for over 30 years.