Zone 3 Neoprene Mens Jammer These jammers can be worn for racing or training and give a slight incrase in bouyancy of the lower limbs whilst mainting a very hydrodynamic profile.  Not to be confused with thicker bouyancy 5mm shorts that are designed for specific sets and drills, these 1.5mm beauties can be worn for the entire session without exaggerating your swimming position. - 1.5mm high quality Yamamoto neoprene - Superstretch lining, can be worn over/ unser or on their own - Can be worn for a degree of extra warmth or bouyancy