P310031 (M-31) PUNCH-LOK® by PT-Coupling | Lok-Mender Hose Fitting | 3/8" Hose Barb x 3/8" Hose Barb | Single Groove | Plated Carbon Steel | 24 Pieces/BoxOverview: PUNCH LOK single and double groove hose fittings of all types are designed and engineered for use with PUNCH LOK clamps to make connections which will withstand high pressure services. The shape of the grooves eliminates damage to the inner wall of the hose. The PUNCH LOK clamp brings the hose wall into the grooves with even compression around the fittings. Carbon steel steam hose fittings are available in sizes ranging from 1 2" to 1" and