The HALO Bassinest Swivel Sleepers custom shaped mattress pad should be covered with this custom bassinet sheet! The sheet is designed to perfectly fit the mattress pad and features an envelope design for a secure fit. Plus, the hourglass shape perfectly fits the custom Bassinest Swivel Sleeper mattress. The Damask print coordinates perfectly with the Bassinest Safer envelope and design wont come loose during use. Machine washable.