ADJUSTABLE BED SHEET FASTENERS: Bed sheet holders made of elastic nylon band in 1 inch or 2.5cm wide. Each triangle bed sheet fastener consists of 3pcs straps, all adjustable from 3.9 to 8.6 inches (10-22cm), with full extension up to approximately 20 inches (50cm). Adjustable mattress corner clips with strong elasticity, adjustable length allows desired tension to fit your every need for the night. PREMIUM BED SHEET FASTENERS: Heavy duty bungee cord lock, nickel plated clamps with plastic grips inside, our bed sheet fasteners hold your bed sheet tight without damage. STABLE TRIANGLE DESIGN: Bed sheet holders in stable triangle design with wide elastic nylon band, stable and able to hold higher load than 2 clips bed sheet fasteners. To fasten, clip the middle clamp on the actual corner of the bed sheet, then clip the other two clamps to the sides of the corners creating a y. Repeat above for all 4 corners and flip the fitted corner back down over the mattress. Adjust the bands to your desired tension. SLEEP IN COMFORT: These bed sheet fasteners hold your sheets and keep corners in place all night long, keep your bed always looks neat. No more sheets coming off and or bunching up all over the bed. These triangle mattress corners clips will end the battle between you and your sheets, giving you better sleeping experience and an easier morning without untuck sheets. WIDELY USE: Our bed sheet fasteners fit with fitted sheet and flat sheet for sizes Twin, Twin XL, Full, Full XL, Queen, King & even up to California King sheets. Use these adjustable mattress corner clips on sofa cover, couch seat cover, car seat cover, chair cover, tablecloths, ironing board covers, slipcovers and so one to make your life easier.