LATICRETE® 3701 Fortified Mortar is a polymer fortified blend of carefully selected polymers, portland cement and graded aggregates. LATICRETE 3701 Fortified Mortar does not require the use of latex admix, you only need to add water to produce thick bed mortar with exceptional strength. LATICRETE 3701 Fortified Mortar Bed is an approved substitute for LATICRETE 226 Thick Bed Mortar mixed with LATICRETE 3701 Mortar Admix.