Haydels Duck Variable Tone Mallard. Closed for older hen open for higher pitch of younger hen. Specifications for Haydels VTM90 Duck Variable Tone Mallard: Mfg Item Num: VTM90 Supplier SKU: 81054 Category: GAME CALLS Type: Reed Call Species: Duck Material: Plastic Battery: None The Haydels VTM90 Duck Variable Tone Mallard is a quality addition to the Haydels lineup. For more great deals on Duck Calls by Haydels please browse our Haydels Hunting Gear page.