WEARINg TIPS] - This is an over-the-head harness and the neck part is not open but its adjustable with 2 adjustment clips Please refer to the size chart to confirm that your dogs head can pass through the harness SIZE gUIDE] - XS: Harness (Neck girth 98A-125A chest girth 11A-15A) collar (Width 06A Length 98A-138A) Leash (Width 06A Length 59A) S: Harness (Neck girth 125A-15A chest girth 135A-18A) collar (Width 08A Length 118A-16A) Leash (Width 08A Length 59A) M: Harness (Neck girth 145A-17A chest girth 16A-21A) collar (Width 08A Length 138A-20A) Leash (Width 08A Length 59A) You can refer to our size chart picture which is more clear to show you the size DOg cOLLAR HARNESS & LEASH] - This is a three-pack set that includes a harness a dog leash and a dog collar all of the same plaid patterns These are the daily necessities for pets and you dont need to spend extra time choosing other accessories NO PULL NO cHOKE] - This harness is ideal for small dogs daily walking cushioned design reduces neck friction and the metal D-ring easily links to leash hooks not easy to swing preventing suffocation and pull quality materials] - The harness is lined with breathable air mesh fabric which always keeps the dogs fur dry and comfortable The outer fabric is made of durable polyester fiber The whole harness is lightweight for small dogs to wear NOTIcE: DO NOT wash at a high temperature otherwise it may cause the fabric to deform or even fall off REFLEcTIVE] - There are 4 reflective strips on the vest harness you can see the reflections from all angles at night which fully guarantees the safety of the dog walking at night and makes the owner no longer worry about the dog being accidental