Quest Replacement Air Filter for PowerDry 4000 & Dual 105, 155, 205, 225 Only Models Replacement MERV 11 filter for the Quest PowerDry 4000 Portable Dehumidifier and Dual 105, 155, 205 & 225 Overhead Dehumidifiers Captures particles (including mold spores) down to 1 micron Filter size is 20 in x 16 in x 2 in