A head wearable device comprising: a headpiece comprising: a headband comprising a top strap and at least two lateral straps (120A, 120B); an occipital basket comprising a strap, the occipital basket being attached to the headband by at least one lateral extension strap (130A, 130B) pivotably attached by a hinge (140A, 140B) to a distal end of each respective lateral strap (120A, 120B) of the headband; a first housing attached to an outer surface of the top strap of the headband; a depth adjuster attached to the first housing, the depth adjuster comprising a first gear rotatably fixed to a first knob; wherein the strap of the occipital basket comprises a slot with a plurality of teeth formed around a longitudinal edge of the slot; wherein the first gear is captively held within the slot and engages with the plurality of teeth; wherein the depth adjuster is configured such that a rotary movement of the first gear causes a longitudinal movement of the strap of the occipital basket to change a distance between the occipital basket and the first housing; wherein a depth of the headpiece changes when the distance between the occipital basket and the first housing changes; and wherein the strap comprises a first visual index comprising a first plurality of sequential characters, each of which correspond to one of a plurality of predetermined depth settings of the headpiece; and a second housing attached to an outer surface of the occipital basket; a headband adjuster at an outer surface of the occipital basket, the headband adjuster comprising a second gear rotatably fixed to a second knob; wherein the lateral extension straps (130A, 130B) each comprise a slot (132A, 132B) with a plurality of teeth (134A, 134B) formed around a longitudinal edge of the slot (132A/132B); wherein the second gear is captively held within the slot (132A, 132B) of each lateral extension strap and engages with the plurality of teeth (134A, 134B) of each of the lateral extension straps; wherein the headband adjuster is configured such that a rotary movement of the second gear causes a longitudinal movement of the lateral extension straps (130A, 130B) to change a circumference of the headpiece; and wherein at least one of the lateral extension straps (130A, 130B) comprises a second visual index comprising a second plurality of sequential characters, each of which correspond to one of a plurality of predetermined circumferential settings of the headpiece; wherein the head wearable device is configured such that the lateral extension straps (130A, 130B) rotate about the hinge (140A, 140B), relative to the lateral straps (120A, 120B) as the depth of the headpiece changes. a headband comprising a top strap and at least two lateral straps (120A, 120B); an occipital basket comprising a strap, the occipital basket being attached to the headband by at least one lateral extension strap (130A, 130B) pivotably attached by a hinge (140A, 140B) to a distal end of each respective lateral strap (120A, 120B) of the headband; a first housing attached to an outer surface of the top strap of the headband; a depth adjuster attached to the first housing, the depth adjuster comprising a first gear rotatably fixed to a first knob; wherein the strap of the occipital basket comprises a slot with a plurality of teeth formed around a longitudinal edge of the slot; wherein the first gear is captively held within the slot and engages with the plurality of teeth; wherein the depth adjuster is configured such that a rotary movement of the first gear causes a longitudinal movement of the strap of the occipital basket to change a distance between the occipital basket and the first housing; wherein a depth of the headpiece changes when the distance between the occipital basket and the first housing changes; and wherein the strap comprises a first visual index comprising a first plurality of sequential characters, each of which correspond to one of a plurality of predetermined depth settings of the headpiece; and a second housing attached to an outer surface of the occipital basket; a headband adjuster at an outer surface of the occipital basket, the headband adjuster comprising a second gear rotatably fixed to a second knob; wherein the lateral extension straps (130A, 130B) each comprise a slot (132A, 132B) with a plurality of teeth (134A, 134B) formed around a longitudinal edge of the slot (132A/132B); wherein the second gear is captively held within the slot (132A, 132B) of each lateral extension strap and engages with the plurality of teeth (134A, 134B) of each of the lateral extension straps; wherein the headband adjuster is configured such that a rotary movement of the second gear causes a longitudinal movement of the lateral extension straps (130A, 130B) to change a circumference of the headpiece; and wherein at least one of the lateral extension straps (130A, 130B) comprises a second visual index comprising a second plurality of sequential characters, each of which correspond to one of a plurality of predetermined circumferential settings of the headpiece; wherein the head wearable device is configured such that the lateral extension straps (130A, 130B) rotate about the hinge (140A, 140B), relative to the lateral straps (120A, 120B) as the depth of the headpiece changes.