Lighting packages include trays, arms, strobes and sync cords. Dual sets include a focus light or a second strobe. Compatible with most manufacturers' housings that have a tripod mount screw. Ikelite UltraCompact, and other larger housings from Sea & Sea or Olympus must use one of the Flat or I-DAS Tray Sets, no other tray fits well. Please see our Light Comparison Specifications Chart for a comparioson guide. Also see our Resource Center article Choosing an Underwater Lighting System, and our free downloadable Handbooks on Underwater Lighting.