The sizes shown above refer to the shell size of the drum, the internal dimensions of all our cases take into account all hardware. All our snare cases will accept a Tom with shell depth up to 1" deeper than the product code depth. EG: a 10" x 10" Tom will fit inside a 4010 - 10" x 9" tom case. All our RIMS cases are 1" larger on their internal diameter to take into your suspension mounting system. The internal depth of the case is the same. Yamaha Y.E.S.S & DW STN mounts DO NOT require RIMS size cases they will fit inside standard cases. If your SMS protrudes over ½" from the shell of your drum, you will require a RIMS size case to accommodate.