Amazon.com: SDTC Tech 8-Pack 18650 Battery Holder with Wire Leads 1/2/3/4 x 3.7V Series Circuit Black Plastic Battery Case Kit (2 Per Size) : Electronics
18650 Series Batteries Holder 18650 SMD SMT Battery Box 18650 Battery Case 1/2/4 Slot
18650 Battery Holders - Keystone | Mouser
4-Way 18650 Battery Holder - DFRobot
18650 Battery Holder | Dual Slot, Series, 2.1mm DC Jack