Comments about Westcott Westcott Spiderlite TD5 50 Watt Protective Lamp Cap.:
Essentially, this covers the lamps while they're still mounted in the TD-5 head so that the entire unit can be packed and hauled without worries about the bulbs being broken in transit. This also, naturally, saves lots of time in set-up and break-down, since it eliminates the need to unscrew all the bulbs and put them in packaging of some type. If you travel with the Wescott TD-5, this is a no-brainer.