Simply submerge the hand or foot in the volumeter. The excess water is caught by the overflow receiver and then measured in the graduated cylinder. The displaced water measures edema accurately, allowing for effective monitoring of edema. Complete set includes a 3" x 5" x 11" (7.6 x 13 x 28cm) Hand Volumeter, an overflow receiver and a 500 ml (17 fl. oz.) graduated cylinder. The Foot Volumeter measures 13" x 5" x 9" (33 x 13x 23 cm). Use the 22" (56cm) long Contoured Scrub Sponge (NC28645), sold separately, to clean the volumeter and containers.