The tried and true Altra Lone Peak is facing some updates in the 4.0 model. A favorite shoe for thru-hikers for its spacious toe-box and comfortable fit, this shoe is seeing some updates in the upper and lower portions of the shoe. One of the biggest updates to the 4.0 model is the outsole. Made with a new rubber compound still branded as Maxtrac, this outsole is grippier and more durable than previous versions. The lugs are more aggressive and less prone to being sheared off on sharp rocks or debris. The midsole of the Lone Peak 4.0 is relatively unchanged. The midsole tapering from the ball of the foot to the toes is now more aggressive, and the TPU StoneGuard rock plate is no longer a plain insert, but rather replicates the bone structure of the foot (think independent metatarsals). The 25-mm stack height and foam firmness have been left unchanged. The upper portion of the shoe that shows change is a single layer mesh with v-shaped overlays that surround the midfoot. This new mesh on the Lone Peak is more durable and has functional stretch for your foot pounding down the trails. Other changes to the upper include more ventilation (undesirable debris won’t be an issue with this new ventilation), a tongue that is moderately padded and perforated, and a toe cap that has two drainage points.