rubber fingers to grip around the item the flexibility and resilient nature of silicone rubber is helpful for this purpose as is the surface texture which having a high coefficient of friction tends to grip the dental instrument depending on the size and shape more than one instrument or appliance may be nested and wedged into the finger mat 46 and as illustrated provisions are made in the design of the tray for the use of two mats as illustrated in fig5 each finger mat 46 has a design which in combination with the sidewalls 24 and 25 of tray 21 permits the finger mat to be installed in the tray with a snap in snap out design tab 65 is sized to fit within lower edge slot 71 disposed at the base of the sidewall 25 just above the top surface of base 23 in tray 21 the finger mat 46 must be tilted at an upwardly inclined angle in order to initiate the insertion of tab 65 into slot 71 the next step is to push the elevated end of the mat downwardly toward base 23 as this step is performed spring clip 66 is in interference with the inside surface of sidewall 24 the spring properties of clip 66 allow it to resiliently deflect inwardly as the finger mat is pushed closer to base 23 the degree of interference and pressure on.