The Profoto Gel Kit for A1 Flash contains four light balancing filters that neatly fit into the supplied Gel Holder, which quickly clicks onto the A1’s magnetic mount. The Full, 1/2 and 1/4 CTO filters are basically graduated conversion filters that warm the A1’s daylight-balanced output. The full gel is a complete conversion to approximately 3200K, while the 1/2 is aggressively warm to match other fixtures, or for creative effect. The 1/4 CTO provides a warm late afternoon look. Lastly, the 1/2 Plus Green filter helps balance the output with fluorescent lights.