Screw size is #10.
0903DP1: Good for polished or burnished models. Fits Fortress Models - FX7-FX16
Danforth* Models - T®11-570, T®11-1200, T®11-1800, T®11-2500, T®11-3000, S®160, S®300, S®600, S®920, S®1300
0903DP2: Fits Fortress Models - FX23-FX55
Danforth* Models - T®11-4000, T®11-6000, T®11-7000, S®1600, S®2000, S®3000, S®3500