X Style Pro Dual Music Keyboard Stand Electronic Piano Double 2-Tier Adjustable | eBay
Amazon.com - Miwayer Keyboard Stand Extension Adapter for X-Style Keyboard Stand, 2 tier keyboard stand Adjustable Width (Keyboard Stand Extension)
Amazon.com: Generic 2 Tier Keyboard Stand Attachment, Second Tier Extension Additional Stand Adapter, Width Adjustable, Black, 47X31X12CM, 1GGE058R2A1874F42179GFWW : Musical Instruments
Quik Lok
Amazon.com: Liquid Stands 2 Tier Keyboard Stand Attachment - Arms Only - Adjustable Electric Digital Piano Stand for 54 - 88 Key Music Keyboards & Synths - Double Stand Extender for Square