The RL786TW is a 4" x 6" weatherproof thermal transfer label on a 3" core with an 8" outer diameter. While we haven't tested the WASP WPT408 to confirm, you'll want to make sure your printer is able to hold a 3" core roll with an outer diameter of 8" and is set to Gap Sensing. If your printer offers both direct thermal and thermal transfer printing, just make sure you have the thermal ribbon installed and the printer set to Thermal Transfer printing if using our thermal transfer materials.