Canon EOS Rebel T4i 18-135mm IS STM Lens Kit Instruction Manual page 342

Use of genuine Canon accessories is recommended
This product is designed to achieve excellent performance when used with
genuine Canon accessories. Canon shall not be liable for any damage to this
product and/or accidents such as fire, etc., caused by the malfunction of non-
genuine Canon accessories (e.g., a leakage and/or explosion of a battery
pack). Please note that this warranty does not apply to repairs arising out of the
malfunction of non-genuine Canon accessories, although you may request
such repairs on a chargeable basis.
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