Vary the insides of your VerSpanken masturbator with these wavy inserts. The wavy texture adds a different dimension to masturbating. These inserts can also be cooled down in the fridge or heated up in the microwave for additional penis thrills. Simply add them to your VerSpanken and adjust the pressure gauge according to your preferred level of tightness. NB. The VerSpanken is sold separately.