We have seen a large number of timers and other accessories with labels made of DUCT tape and medical tape. Please considor that the glue from these tapes hardens and becomes very difficult to remove. If you do not have access to a P-touch or similar label maker, use a product called Artist Tape. Artist Tape is a nice version of masking tape that sound engineers for bands use to label all of their equipment. It looks good and peels off without leaving residue.