You should get the King box spring encasements. The king box spring encasement includes two encasements measuring 38x80x9 each. The regular twin size (38x74x9) will be too short.
The King size box spring encasements are actually Twin XL box spring encasements. There are two box springs underneath a King size bed, and the King box spring encasement is actually two Twin XL encasements that measure 38 x 80 x 9 each.
The Protect-A-Bed Box Spring Covers are made out of polypropylene, a soft bedbug proof material. Each cover completely encases the box spring.
No. You will need to order the California King Size box spring encasements. We do carry California King mattress and box spring covers.