A syringe, comprising: a body (121, 1021) having a first portion (122, 1022) and a second portion (124, 1024), said first portion (122, 1022) receiving a medicament, said first portion (122, 1022) having a first diameter and said second portion (124, 1024) having a second diameter, said first diameter being smaller than said second diameter; a collar (141, 1041) rotatably disposed in said body (121, 1021), said collar (141, 1041) being rotatable to set a desired dose of medication drawn into said first portion (122, 1022); a plunger (161, 1061) movably connected to said collar (141, 1041), said plunger (161, 1061) having a plunger rod (163, 1063); and a stopper (171, 1071) disposed at an end of said plunger rod (163, 1063) to facilitate drawing in and dispensing the medicament, wherein said collar (141, 1041) has a first end (148, 1048), a second end (149, 1049), and a bore (146, 1046) passing through said collar (141, 1041) from said first end (148, 1048) to said second end (149, 1049) to receive said plunger rod (163, 1063) therethrough, wherein an outer surface (142, 1042) of said collar (141, 1041) has a threaded portion to engage a corresponding threaded portion on an inner surface of said second portion (124, 1024) of said body, characterized in that said second end (149, 1049) of said collar (141, 1041) has a smaller diameter than said threaded portion of said collar (141, 1041), said second end (149, 1049) of said collar (141, 1041) being disposed in said first portion of said body (121, 1021), said second end (149, 1049) acting as a mechanical stop for said plunger (161, 1061) by abutting said stopper (171, 1071) when pulling said plunger (161, 1061) out of said collar (141, 1041), thereby limiting the medication drawn into said body to said set desired dose. a body (121, 1021) having a first portion (122, 1022) and a second portion (124, 1024), said first portion (122, 1022) receiving a medicament, said first portion (122, 1022) having a first diameter and said second portion (124, 1024) having a second diameter, said first diameter being smaller than said second diameter; a collar (141, 1041) rotatably disposed in said body (121, 1021), said collar (141, 1041) being rotatable to set a desired dose of medication drawn into said first portion (122, 1022); a plunger (161, 1061) movably connected to said collar (141, 1041), said plunger (161, 1061) having a plunger rod (163, 1063); and a stopper (171, 1071) disposed at an end of said plunger rod (163, 1063) to facilitate drawing in and dispensing the medicament, wherein said collar (141, 1041) has a first end (148, 1048), a second end (149, 1049), and a bore (146, 1046) passing through said collar (141, 1041) from said first end (148, 1048) to said second end (149, 1049) to receive said plunger rod (163, 1063) therethrough, wherein an outer surface (142, 1042) of said collar (141, 1041) has a threaded portion to engage a corresponding threaded portion on an inner surface of said second portion (124, 1024) of said body, characterized in that said second end (149, 1049) of said collar (141, 1041) has a smaller diameter than said threaded portion of said collar (141, 1041), said second end (149, 1049) of said collar (141, 1041) being disposed in said first portion of said body (121, 1021), said second end (149, 1049) acting as a mechanical stop for said plunger (161, 1061) by abutting said stopper (171, 1071) when pulling said plunger (161, 1061) out of said collar (141, 1041), thereby limiting the medication drawn into said body to said set desired dose.