Nexcare Absolute Waterproof Tape is a good tape to have in the kit for skin mounted lav mics when situations are going to get wet or sweaty.  It also works well in combination with Moleskin to add an extra layer of cushion.  It tends to work best if applied onto dry skin prior to the wet or sweaty situation.  The roll is 1 inch x 5 yards.   

FEATURES

• Cushioned protection
• Flexes and stretches with your body
• Sticks - even when wet
• Breathable for added comfort
• Hypoallergenic
• Dermatologist tested
• Made in the U.S.A.