Durable Bed Clip: The mattress clips consist of sturdy metal clips and three durable black elastics, each with a soft plastic clip to protect the fabric Stable Triangle Design: Stable triangle design, prevent sheets from coming undone. The fitted sheet straps to keep your sheets taut and keep it in place every day, without having to readjust them every night Adjustable length: The length of the elastic band is adjustable from 10 cm to 18 cm. Holds the sheets in place without the need for additional fixings, length can be adjusted according to the desired tension 4.Easy to Use: Easy to install, attach the tensioners to each corner of the sheet by positioning its ends about fifteen meters angle on all three edges that extend from it Versatile Compatibility: Simply clip an elastic band with loop to each corner of the mattress. Suitable for all types of mattresses, standard beds, inflatable mattresses, sofa beds, RV beds etc.